What are the legal scopes of car modifications?
3 Answers
Changing the body color, interior, and car wheels are all considered legal car modifications. The illegal modification scopes and precautions are as follows: Illegal modification scopes: Modifications to the vehicle's braking system, power system, and suspension system, which affect the safety level of the car, are not allowed; the car model, engine model, and frame number cannot be modified, and the body structure must not be damaged. Precautions for modifications: If the car's color is changed, or the engine, body, or frame is replaced, the car must be inspected. Replacing the engine, body, or frame also requires submitting a qualified motor vehicle safety technical inspection certificate; additionally, the area of car stickers must not exceed 30% of the total body area.
Last time I modified my car, I specifically researched the new regulations. Now I’m sharing my experience. You can change the body color but need to register it—just avoid using colors reserved for special vehicles. You can replace the rims with the same size; larger rims look cool but will definitely fail the inspection. Decals should not cover more than 30% of the body. Feel free to modify the interior as long as you don’t alter the number of seats. Be extra careful with exhaust modifications—those that are too loud will get you pulled over by the police. Any modifications to the engine, turbo, or other power systems are illegal. Last time, a friend got fined 2,000 yuan for tuning the ECU. Also, don’t randomly upgrade to xenon lights, especially blue or purple ones—they’re dangerously blinding at night. Remember to check the local DMV website before modifying, as policies vary by region.
Watching my neighbor modify cars for over a decade, the legal boundaries are actually quite narrow. Cosmetically, only stickers and color changes are allowed—these are just surface-level modifications. Structural components are completely off-limits. Some people install widebody kits and immediately fail their annual inspections, and increasing wheel size is also considered illegal. Headlight modifications are the easiest to get wrong—swapping factory halogen lights for LEDs will definitely fail inspection. Adding a large rear spoiler might look cool, but anything excessively long or wide is absolutely illegal. Never touch the exhaust system, especially those loud, roaring street versions—sound-detecting cameras are everywhere now. The interior is a bit more lenient; as long as you don’t remove airbags or tamper with wiring, it’s generally fine. Before diving into modifications, it’s best to consult experienced mechanics—they know the local policy redlines best.
