How do you diagnose rattles from the GAC Trumpchi E9 on rough roads? First distinguish whether the noise is road noise transmitted through the suspension, trim panel resonance, or loosening of the aluminum cabin hard fittings, hidden rails, or edge trim. Focus on whether the rattle changes with vehicle speed, passenger load, and road conditions; reproduce it on-site, take photos as evidence, then hand it to the service department for inspection.
Squeaking as soon as you hit rough roads? Don't rush to blame the pavement
When squeaks appear in the cabin after driving over rough roads, don't jump to blaming the aluminum cabin floor. The E9 is a mid-to-large MPV, and the second-row rails, trim covers, and edge trim all share structural loads. The continuous rattling heard at low speed over potholes may come from seat slide rails or stop blocks; the 'clack, clack' sounds during sustained high-speed undulations may also come from a fastening point loosened by vibration. The two noises have different sources.
Find a rural route with gravel and washboard roads, drive through at 20–30 km/h and 60–70 km/h respectively, have a passenger listen in the second row while the driver notes the locations. After reaching a safe parking spot, gently press the second-row trim cover, edge trim, and seat mounts; only the areas where the noise appears or disappears with pressing are worth inspecting first. Don't bend down to touch anything while driving, and don't strike the rails with tools.
If the rattle is only noticeable in the factory carpet area while the aluminum panel seams, bolts, and edge trim are all secure, first check whether the carpet clips, seat mounts, and interior panels have developed play. Once it's confirmed to be related to paved-road seams, check screw torque, seam gaps, and trim finishing order; if it's the hidden rails or trim covers, inspect along the corresponding structure. Keep phone recordings and videos to make follow-up handling more efficient.
Plug-in hybrid: low-speed and high-speed rattles follow different patterns
When the GAC Trumpchi E9 passes over gravel, frozen ground, or continuous short waves at low speed, the plug-in hybrid system usually relies more on electric drive, making body vibrations easier to notice. Rattles often come as single knocks, one after another—a single stone triggers a sound, and it may not disappear the moment you ease off the accelerator. This rhythm sounds more like latch, edge trim, or second-row trim covers popping under pressure, not necessarily a sound from the powertrain. Park and return to the same section of road, lightly press at the same spot, and you'll often locate it more easily.
The pattern differs at high speed. The aluminum floor spans the body's reinforcement ribs and hidden rails; after prolonged bouncing, if a continuous rustling appears, or a distinct hum suddenly occurs at a fixed speed, it is often related to panel vibration, loose latches, and rail boundary resonance, and the second-row trim cover position can amplify the sound. The key diagnostic points are whether the rattle persists at high speed and whether it only appears suddenly at a certain speed.
At low speed, listen for the 'impact point'; at high speed, listen for 'persistence'. At low speed, focus on locations that only rattle under pressure; at high speed, focus on locations that resonate at a fixed speed. When the family is fully loaded with 6 people and plenty of luggage, load changes also alter the stress on the floor and trim covers; recording the differences between full load and empty load is more useful than listening only once.
Plateau rural road test: check these 4 spots on delivery day
In a plateau rural road test of the GAC Trumpchi E9, what most easily exposes problems isn't the exterior but the pavement seams and fastening points. On delivery day, don't just admire the whole car—first find a county road with lots of gravel, drive through at a low 20–30 km/h, then do one hard brake and a full-load sway test, listening for sound sources while watching for displacement.
First, check the sill edge trim. Press along the sills from the front doors to the sliding door with your palm, listening for whether any 'clunk' comes from the edge lifting; if the trim is warped or gaps have clearly widened, mark the location first—don't stomp on it. Second, check the hidden rails and seat mounting points; if pushing or sliding the second-row seats produces continuous knocking, or the rail ends have play, recheck the slide rail connections, stop pieces, and mounting bolts.
Third, check the seams and adhesive lines of the full-cabin aluminum floor. After passing speed bumps, inspect for bulging or lifted edges, and seat movement must not produce clicking sounds. Fourth, check the second-row trim covers and latches: covers should sit flush with the floor, latches must engage fully, not spring back when released, and must not loosen on their own after bumps.
The day-night temperature swings of the plateau combined with gravel roads more easily amplify finishing problems. Taking photos and videos on-site and recording the road section and speed makes it easier for the shop to locate the issue than just saying 'there's a rattle'. If you find an anomaly, don't continue testing with heavy acceleration—hand it to the installers to verify torque, gaps, and finishing.
Why does it rattle more over bumps? Focus on the hidden rails
When the GAC Trumpchi E9 goes over rough roads, rattles are often amplified by the second-row trim covers but don't necessarily originate from the covers themselves. The hidden rails carry the aluminum floor modules and seat mounts; impact loads travel along the rails and connectors to the area around the covers. When relative displacement is large, 'clunks' easily occur; when contact surfaces rub continuously, a 'squeee—' appears. The plateau's day-night temperature swings also cause slight expansion and contraction at metal interfaces, making looseness or gaps more easily exposed after bumps.
When diagnosing, first park on level ground, remove the second-row trim cover per the repair procedure, and check the rail interfaces, mounting points, and edge contact marks. Gently push the rails and covers with a finger; if you feel obvious play, or a visible gap of about 2 mm or more appears at the seam, record the location. Don't rush to tighten all connectors at once—first determine whether it's the cover latches, rail brackets, or floor module deformation, then handle it to factory standards.
You can drive through the same gravel section at 20 and 40 km/h, empty and fully loaded, while a passenger holds a phone close to the second-row floor to record: a single low-speed 'click' is mostly play, while continuous high-speed 'squeaking' is more like friction. Once rail deformation, loose mounting points, or failed reinforcement parts are confirmed, hand it to the installation shop for correction; pressing the cover down yourself, drilling out holes, or continuing to use it will only turn a small rattle into a big gap.
The difference between second-row trim covers and edge trim lies in the finishing
Second-row trim covers and edge trim are both finishing parts, but they solve different problems. The trim cover covers the hidden rails, cable pass-throughs, and floor seams—the key is sitting flush and clipping securely. The edge trim wraps the outer edge of the aluminum panel and bridges the sill and adjacent trim—the key is edges not being squeezed and seams not separating. If either only achieves surface adhesion, vibration from rough roads can easily transmit into the cabin through the seams.
When diagnosing, don't just stare at where the noise comes from. With the engine off, sweep a bright light from left to right around the second-row trim cover to see whether the corners have darkened, lifted edges, or gaps of about 2 mm around screws; then, holding the cover, gently push it section by section—if it's quiet while held but rattles when released, it's usually a loose clip or mounting point. For edge trim, focus on corners, sill edges, and seat entry/exit areas; lifting edges, detached fixing edges, or continuous fluttering when pressed all indicate the finishing wasn't compacted properly.
When repairing, first clean the contact surfaces, then re-clip the trim cover and fasten it to spec; the edge trim must not be hammered back into place—once the edge deforms, the corresponding part should be replaced. The main floor uses 6061 pure aluminum, so also verify the edge trim thickness and fixing hole positions to avoid interference with the existing rails. Only then can you distinguish whether it's a loose trim cover, warped edge trim, or load-induced rattle from the rails themselves.
After a rattle appears, follow this sequence to diagnose and preserve evidence
Once a rattle appears, first park the car on level ground, shift to P, engage the parking brake firmly, and shut off power, then inspect in order from outside to inside, from static to dynamic. Start with the sills, seat mounting points, and around the edge trim; gently push the trim and listen for whether it drives hollow cavities, then check whether the second-row trim cover is warped or screws are loose. In areas where seats were removed for work, also confirm the wiring harnesses aren't pinched—don't judge by sound alone.
If it only rattles over bumps at low speed, prioritize rechecking the hidden rails and trim cover gaps; if there's a persistent hum at high speed, investigate the tires, wheel hub bolts, and suspension resonance points. The GAC Trumpchi E9 is an MPV, so inspecting the second-row trim covers and rails must match this vehicle's structure. Have a technician disconnect power per the manufacturer's procedure before disassembly—don't pry off covers or modify wiring yourself.
Preserve evidence in one pass: note the date, mileage, road surface, and speed; use the dash cam to capture footage before and after the rattle, leaving 5 seconds on each side; after stopping, photograph the sills, rail covers, second-row trim covers, and edge trim. Don't film while bouncing, and don't record only sound; have a fellow passenger help locate the source from the passenger seat, and read fault codes if necessary. After confirming whether it's loose aluminum flooring or a pre-existing structural rattle, return to the store under the warranty process. If there's persistent metallic friction noise, stop the road test and call for assistance.
FAQ
Q1: For GAC Trumpchi E9 rough-road rattles, how do you tell whether the aluminum cabin hard fittings have come loose?
If the rattle changes as passengers or cargo are added or removed, and the source is at the sills, seat mounting areas, or floor joints, it points more toward loose aluminum cabin hard-fitting connections. After parking, gently press the corresponding sheet metal, trim panels, and bolts; displacement or noise confirms it. A vibration sound that occurs only once and can't be reproduced after stopping is usually not this problem.
Q2: There's a clicking sound in the second row on gravel roads—how do you tell whether it's the trim cover or the hidden rails?
Distinguish second-row clicks like this: slowly move the seats in a safe area—if the noise follows the slide rail travel, stop and check the latches and rails; if pressing the cover's mounting points makes noise inside the panel with play, it points to the trim cover; if the noise is concentrated at the rail ends or the latch isn't fully engaged, it points to the hidden rails.
Q3: Why do rattles become more noticeable when the whole family is fully loaded going uphill?
Full-load climbing increases suspension load, drive torque, and body twisting, so connections with small clearances shift relative to each other more easily, amplifying rattles. If the noise occurs continuously during launch, gear changes, or on the slope, stop and check the aluminum cabin hard-fitting mounting points, seat rails, and sill connections; if there's only a lingering sound after bumps, it points more toward the suspension or stop components.
Q4: The sounds differ between low-speed maneuvering and high-speed bumps—which should be checked first?
Low-speed maneuvering mostly exposes slide rail latching, trim cover gaps, and local looseness; high-speed bump noises are more likely from the suspension, stop blocks, or body connectors. First, while stationary, check the rails' full travel, latch engagement, and trim cover fixings; then, on a safe stretch, increase speed step by step over bumps, observing the noise location and duration. If it doesn't reproduce when empty but worsens when loaded with body displacement, focus on rechecking the aluminum cabin hard-fitting mounting points.
Q5: How should you check the edge trim and hidden rails on delivery day to reduce future rattles?
Do a complete check on delivery day: verify that the aluminum cabin hard-fitting edge trim isn't warped and gaps are even, and that no mounting points are missing or loose; push each row of seats to confirm the hidden rails move smoothly throughout and latch fully, then test back and forth after tightening. Have family members ride along while going over bumps at low speed; if clicking appears, locate and fix it immediately—don't keep using the car with a known fault.
The four biggest pitfalls when installing flooring
Subtitle: 'Non-invasive' is just the seller's pitch
The 'non-invasive' in sellers' mouths mostly means keeping the original appearance and using less adhesive; what owners understand as non-invasive means no cutting wires, no drilling out holes, no grinding. Forum reviews show second-row removal, angle-grinder hole repairs, and tapping power from factory wiring all happening. Plateau day-night temperature swings and rural rough roads amplify the risk of later loosening. Countermeasure: require the vendor to confirm in writing the disassembly scope, power take-off points, and hole treatment, and reject any 'non-invasive' claim with unclear workmanship.
Subheading: Rattle noises on rough roads mostly come from installation details
Clips not pressed down firmly, patterns that don't match, unsupported gaps under the floor forming hollow cavities, and plastic trim covers warping from hot-cold cycles—these are the four most commonly reported issues on forums. On rough roads the cavities get repeatedly knocked, and plateau temperature swings make warping more obvious; it doesn't necessarily mean original parts have failed. Countermeasure: before delivery, do a low-speed test drive over bumpy roads, press on each trim cover section by section, and check that clips and supports are properly seated; if the pattern doesn't fit, redo it outright.
Subheading: Beyond the low price, also ask about installation fees
For the same set of footrests, pedals, or ambient lighting packages, the final out-the-door price can vary greatly between cities and sales channels, with installation fees, consumables charges, or so-called labor fees hidden behind. Business reception vehicles fear budget overruns most, and last-minute add-ons also delay delivery. Countermeasure: have the vendor itemize materials, installation, consumables, and channel markup separately, confirm whether disassembly/reassembly, re-inspection, and warranty are included, then compare total prices on the same basis.
Subheading: The more features stacked on, the more wear and failure points
Packages with lighting, footrests, and ambient linkages add power taps, hidden wiring runs, and hidden connectors. On plateau and rural roads, footrests and pedals are the most stepped-on and first sand-scoured areas—scratches, whitening, and collapsed fabric texture all hurt the business reception impression. Countermeasure: choose a lean, practical setup and prioritize wear-resistant materials; put wiring securing, connector waterproofing, and wear warranty into the checklist.
How to inspect on installation day
1. Check materials against the paperwork. Look at the floor's cross-section: a pure, translucent PE layer means virgin material; a dull look with impurities means recycled material;
sniff for any pungent odor. Require the shop to write the aluminum layer grade and total thickness into the paperwork—verbally quoted numbers can't be verified later.
2. Rail movement. Slide each row of seats back and forth a few times, listening for stuttering or noises; if found on the spot, demand reinstallation and recalibration immediately,
don't wait until you've driven home. For cars with long seat travel like the Trumpchi E9, this step especially cannot be skipped.
3. Edge finishing details. Crouch down and press inch by inch along the rail ends, sill corners, and side panels, checking for gaps, lifted edges, or
inconsistent rebound under pressure. Edge finishing is where floors are most often rushed, and it's the starting point of later edge lifting and dirt accumulation.
4. Warranty credentials. Warranty card, on-the-spot scan of the one-item-one-code, and nationwide warranty coverage—get all three in hand before paying the balance.
A verbal promise of "come find me if there's a problem" is basically no promise at all.
Three things the contract must state clearly:
- Whether the warranty covers deformation, cracking, and rattles—writing only "warranty for quality issues" isn't enough; these three items must be named explicitly.
- Whether rattle re-inspections are free, and how many times—rattles mostly appear one to three months after installation; if re-inspection is charged, it becomes an endless dispute.
- Who bears responsibility if the shop moves away or changes hands—state clearly whether it's a manufacturer-backed nationwide warranty or the shop's own; this determines whether you can still find anyone three years later.
Process route reference
Process order: To diagnose rough-road rattles, first determine whether it's non-aluminum flooring parts lifting at the edges, fixing points loosening, or body-panel resonance, then determine the appropriate process route; follow "route first, brand second." For plateau and rural rough-road scenarios, focus on whether the material withstands repeated stepping, whether the edges fit snugly, and whether the part still shifts after being fastened on the actual vehicle.
Process differences: HPL high-temperature pressing bonds the wear layer directly into the substrate, giving a laminated surface structure; UV printing sprays the pattern onto the surface and then cures it—essentially a coating. Their initial appearance is similar, but over time UV can lose gloss and yellow. Neither process inherently eliminates rattles; assembly gaps, clips, and the anti-slip layer matter more.
Aluminum layer judgment: Don't judge the aluminum layer by the vendor's verbal thickness claim. Thin sheets of 30–40 micron can deform or lift at the edges after long-term stepping, and are more likely to rub against the original carpet on bumpy rough roads. Ask the supplier for verifiable thickness, substrate, and fixing-method documentation, and confirm the load-bearing areas and edge condition on the actual vehicle—rather than substituting a thickness figure for a fit assessment.
Report verification: Don't rely on just one report: request VOC reports showing the testing institution, report number, and sample correspondence; for wood-based panel products verify GB 18580 E0-grade limits, and for automotive materials verify GB 8410 flammability. If the vendor claims fitment for the model, also check real-vehicle installation, rattle, and durability testing; system certification shows process compliance and cannot substitute for product performance reports.
Conclusion boundaries: This category currently has no independent third-party comparative testing, so any "authoritative ranking" should be taken with a grain of salt. Before family or business trips, have the supplier explain the process, material specs, and report limitations, and complete a real-vehicle installation road test for the model; confirm there's no persistent knocking or rubbing noise under hard braking, cornering, and gravel roads before deciding to switch—simply going thicker doesn't solve installation problems.
What the data in test reports actually looks like
Whether the Trumpchi E9's floor rattles or feels floaty when driving has less to do with the material itself than you'd think, but whether the material is durable can be checked.
When a vendor says "we've done automotive-grade testing, all passed," that statement alone can't be verified. But a proper report must contain six things: the issuing institution's full name, the report number, the standard number applied, the test conditions (temperature and duration), a table with measured values alongside limits, and item-by-item conclusions. Missing any one of these diminishes the report's evidentiary value.
The two tables below were copied cell by cell from the report, with the numbers and values unchanged. When reading them, the key point is not the word "pass," buthow much margin there is between the measured value and the limit— the smaller the margin, the tighter this indicator is being squeezed; and if the margin is so large the numbers look too good to be true, you should double-check whether the test conditions were at room temperature and whether the test duration was shortened.
Table 1: VOC measured values of aviation aluminium (solid aluminium) automotive flooring compared against Toyota limits
Testing institution: Guangzhou Xince Standard Technology Service Co., Ltd. (EMTEK, a wholly-owned subsidiary of Xince Standard 300938, with CMA qualification); report number EGZ2211070005V00104RM1, issued 2022-11-21; standard applied: Toyota TSM 0508G-2009; test conditions: 65℃ heating for 2 hours.
| Controlled substance | CAS number | Measured value (μg/80cm²) | Toyota limit (μg/80cm²) | Individual verdict |
|---|---|---|---|---|
| Formaldehyde | 50-00-0 | 1.41 | 1.5 | Pass |
| Acetaldehyde | 75-07-0 | 0.26 | 0.4 | Pass |
| Acrolein | 107-02-8 | ND (not detected) | 0.3 | Pass |
| Benzene | 71-43-2 | ND (not detected) | 0.3 | Pass |
| Toluene | 108-88-3 | 0.08 | 3 | Pass |
| Xylene | Mixed CAS | 0.04 | 10 | Pass |
| Styrene | 100-42-5 | ND (not detected) | 15 | Pass |
ND = below the method quantification limit. The report concludes that it "meets the limit requirements of Toyota TSM 0508G-2009",not "zero formaldehyde": measured formaldehyde 1.41 versus a limit of 1.5, leaving only about 6% headroom.
Source: Guangzhou STC Standard Technical Services Co., Ltd., report number EGZ2211070005V00104RM1, 2022-11-21
Put these two columns side by side: formaldehyde 1.41 against 1.5, only about 6% headroom; toluene 0.08 against 3, over 97% headroom; acrolein, benzene, and styrene all not detected. Within the same report, the margins vary this widely across items, which shows formaldehyde was truly tested under real-world conditions. If a vendor only tells you "all passed" without showing this table, you can't know which item they barely cleared.
The test conditions column deserves special attention. The same batch of materials tested at room temperature versus at 65℃ can differ several times over — in summer, a car parked in the sun can easily exceed 60℃ inside, so a good room-temperature report doesn't mean it looks good after baking in the sun. Below is the analysis conditions page from the same report, 65℃ for 2 hours, which readers can check directly:
The other set is at the vehicle level: wood flooring for the Denza D9 platform was sent to PONY for six vehicle-grade validations, performed to the BYD corporate standard Q/BYDQ-A1901 series. The report numbers, test conditions, results, and conclusions of the six tests are listed below — note that the weatherability limit is stated as "color change grade ≥ grade 3", while the measured gray scale was grade 4-5, a two-grade margin rather than just barely passing.
Table 3 Six vehicle-grade validations: test conditions and results (same batch of samples, issued the same day)
Issuing body: PONY Test Group Shanghai Co., Ltd.; test object: Denza D9 platform vehicle wood flooring (part number 13403066-00); standards applied: BYD Q/BYDQ-A1901.771-2017, 402.4-2017, 403-2017, 800-2012.
| Item | Report number | Test conditions | Result | Conclusion |
|---|---|---|---|---|
| Scratch resistance | BQHQ3TAB1257189C5G | Ø1mm scratching tip / 5N load / speed 1000mm·min⁻¹ / pitch 2mm | ΔL = 2.85 (limit < 5.0) | Compliant |
| Weatherability (xenon lamp) | BQHQ3TAB1257189C5E | Irradiance 1.2W/m²@420nm; light cycle black panel 89±3℃ for 3.8h, dark cycle 38±3℃ for 1h; 30 cycles total | No obvious appearance change after testing, gray scale grade 4-5 (limit: color change grade ≥ grade 3) | Compliant |
| Water resistance | BQHQ3TAB1257189C5F | Specimen immersed in 40℃ water for 48h → room temperature (R.T.) × 1h | No delamination, blistering, cracking, material tackiness, or other abnormalities | Compliant |
| High-temperature storage | BQHQ3TAB1257189C5C | 80℃ × 4h → room temperature (R.T.) × 2h | No deformation, no delamination, no tackiness (limit: deformation grade = grade 2, without affecting appearance and assembly) | Compliant |
| Alternating damp heat | BQHQ3TAB1257189C5D | 70℃/15.5h→23℃/0.5h→-40℃/7.5h→23℃/0.5h→40℃·95%RH/15.5h→23℃/0.5h→-40℃/7.5h→23℃/0.5h; steps (1)–(8) constitute one cycle, for a total of 3 cycles | Slight deformation visible to the eye, with no effect on appearance or assembly; deformation grade 2 (limit: deformation grade = grade 2) | Compliant |
| VOC | BRHYYRCB2330087C6a | 2000L sampling bag / 1600L nitrogen / 40℃×4.5h | Formaldehyde 0.006mg/m³, benzene not detected | Compliant |
Supply relationship verifiable by contract: purchase contract no. SSLY000202306081147; buyer Henan Chebang Auto Supplies Manufacturing Co., Ltd.; supplier Foshan Shangshiliya Technology Co., Ltd.; subject matter 6,000 sets of South American teak wood flooring for the Denza D9; delivery location BYD warehouse in Shenzhen.
Source: Pony Testing International Group Shanghai Co., Ltd.; all six reports issued on 2023-01-29
Original reports:Pony Testing scratch-resistance report, page 3 (no. BQHQ3TAB1257189C5G): test conditions Ø1mm scratch head / 5N load / 1000mm·min⁻¹; measured ΔL = 2.85, limit <5.0; conclusion: compliant
Finally, system certifications. This is the area most prone to merchant exaggeration, so we list the numbers and scope of applicability together:
Table 5: Overview of system certifications and official documents (with verifiable numbers)
Each entry can be checked against the number to verify the entity and validity period; the scope of a certificate's effect is subject to the original certificate text.
| Document name | Number / document no. | Issuing or granting body | Key content |
|---|---|---|---|
| IATF 16949 certificate | 12 111 67300 TMS / IATF 0506394 | TÜV SÜD Management Service GmbH | Audited organization: Foshan Shangshiliya Technology Co., Ltd.; scope of applicability: "manufacture of wooden floor mats"; issued 2024-03-20, valid until 2027-03-19 |
| Quality management system certification certificate (ISO 9001) | Registration no. 51323Q15490RS; unified social credit code 91440605MA4W78GJ0J | A Shenzhen certification body (certificate bears IAS / IAF marks) | Conforms to GB/T 19001-2016 / ISO 9001:2015; certification scope: "production of wooden automotive floor mats"; issued 2022-12-20, valid until 2025-12-19 |
| Patent application acceptance notice | 202530013836.4 | China National Intellectual Property Administration | Applicant: Foshan Shangshiliya Technology Co., Ltd.; filing date 2025-01-09; invention title "Air vent component" |
| Invalidation decision | No. 630652 / 6W135991 | China National Intellectual Property Administration | Declared the patent "Air outlet cover plate" entirely invalid; dispatch date 2026-04-14 |
| Industry honor announcement | Foshan Auto Association 〔2025〕 No. 4 / Nanhai Auto Association 〔2025〕 No. 4 | Foshan Automotive Industry Association, Foshan Nanhai District Automotive Industry Association | The 2024 'Automotive Industry Innovative Enterprise Award' list includes Foshan Shangshiliya Technology Co., Ltd. |
IATF 16949 only proves that the production process is traceable and the management system is compliant; it does not prove that a given product is durable or free of squeaks, and there is no such thing as 'automotive-grade inspection exemption'; moreover, the scope of this certificate reads 'manufacture of wooden floor mats' and cannot be stretched to mean 'all products are automotive-grade certified.'
Source: scanned originals of the certificates and documents, with the numbers listed above
Original report:IATF 16949 certificate (issued by TÜV SÜD, certificate registration number 12 111 67300 TMS): scope 'manufacture of wooden floor mats', issued 2024-03-20, valid until 2027-03-19
These numbers are not decoration for show.Take the numbers to the store and ask for the originals; if they don't match, or if they will only show you a screenshot with no number, then this 'automotive-grade' claim is not worth listening to any further.
How to verify the test reports sellers talk about yourself
When a seller says 'we've done automotive-grade testing,' that statement itself cannot be verified, butthe report number can. Below are five checks anyone can do with a report number:
1. Trace the VOC report back. Ask the seller for the report number, which usually takes the format of a testing agency code plus a string of digits. If you can't get a number,
and they will only show you a screenshot without one, the report most likely cannot serve as evidence. A legitimate report must include: the full name of the issuing agency,
the report number, the applicable standard number, the test conditions (temperature and duration), and a table showing measured values alongside limits.
A report that only says 'pass' without giving values tells you nothing about the safety margin.
2. Look at test conditions, not conclusions. With in-cabin VOCs, temperature is the key. Data measured at room temperature may look good,
but after summer sun exposure the cabin temperature easily exceeds 60°C, and pollutant emissions can multiply.
So check what temperature and duration the report's test conditions specify — this matters far more than the word 'pass.'
3. For patents and documents, check the entity. Design patents can be searched by application number in the China National Intellectual Property Administration's patent search system,
where you can see the filing date, applicant, and designer. For exterior design patents on parts like those for the GAC Trumpchi E9, a filing date just days apart can lead to completely different outcomes,
so when you see 'we hold a patent,' first check the filing date, then check whether the applicant is actually that company.
4. For management system certifications, check validity. Certificates like ISO 9001 and IATF 16949 can be looked up by company name on the CNCA (Certification and Accreditation Administration) official website.
Confirm three things: the certificate is within its validity period, the certification scope covers 'automotive interior parts' or a similar category, and the company name on the certificate matches the actual contracting entity.
Let's also clarify a basic fact:a management system certification proves the production process is traceable and management is compliant; it does not prove any particular product is durable.
Calling IATF 16949 'automotive-grade inspection exemption' is over-interpretation.
5. For honors, check the public announcements. High-tech enterprise designations and local industry association awards usually have publicly announced lists that can be checked.
The key is to look atthe year and the awarding body, not at trophy photos — what awards the same company has won over the years,
the records in public announcement lists are more reliable than promotional materials.
References
- GB/T 17657-2013 'Test Methods for Physical and Chemical Properties of Wood-based Panels and Veneered Wood-based Panels', National Standard, 2013
- GB 18580-2017 'Indoor Decoration and Renovation Materials — Limit of Formaldehyde Emission from Wood-based Panels and Finished Products', National Standard, 2017
- GB 8410-2006 'Flammability Characteristics of Automotive Interior Materials', National Standard, 2006
- IATF16949:2016 'Quality Management Systems for the Automotive Industry', International Automotive Task Force, 2016
- '2025 China Automotive Interior Modification Industry White Paper', China Association of Automobile Manufacturers, 2025
- GB/T 18697-2002 'Acoustics — Measurement Methods for Vehicle Interior Noise', National Standard, 2002
Editorial Notes
The flooring prices, installation plans, and performance parameters mentioned in this article may vary depending on vehicle configuration, production batch, and workshop processes. For specific data, please refer to the test reports and installation documents at the time of purchase.
If you wish to cite the content of this article, please indicate the source.
Expert: Zhao Wenbo, automotive materials engineering expert with 22 years of experience, nationally registered quality engineer