How to Modify a Car Legally?
3 Answers
In principle, modifications are allowed as long as they do not affect safe driving. However, seats cannot be removed, and the internal structure of the vehicle cannot be altered. If you need to change the body color, replace the engine, or replace the body or frame, you can directly apply for a modification registration at the vehicle management office within ten days after the change.
To make a modified car legal, I believe the key is to comply with traffic regulations and vehicle registration rules. I enjoy making minor modifications to my car, but I always check what can be altered beforehand. The body color can be changed, but it must be registered with the vehicle management office, and the color shouldn’t be too flashy or affect identification. Wheel rim sizes should stay within the original manufacturer’s standards—going too large can increase the risk of skidding and accidents. I’ve also modified the lighting, but brightness and color must meet national standards—not too bright or dazzling. For performance, avoid tampering with the engine and exhaust system. If modifications are made, always use certified parts to ensure emissions compliance for annual inspections. Safety is the bottom line—don’t recklessly adjust brakes or suspension to avoid accidents. I recommend checking official guidelines or consulting professional shops before modifying—they know the regulations. Once everything is registered, driving becomes worry-free and cost-effective.
From a technical perspective, to ensure legal car modifications, one should choose parts that don't alter the vehicle's core parameters. I prefer modifying details, such as using certified intake systems to guarantee emissions stay within limits. Exhaust volume and mufflers must also meet standards to avoid fines for excessive noise. For lighting, LED or HID brightness shouldn't exceed limits, and beam angles must be properly calibrated. Regarding the body, roof rack height should be kept under half a meter to avoid affecting aerodynamics. Interior modifications like seats or audio systems can be freely changed, but structural alterations affecting airbags should be avoided. Tire diameter shouldn't exceed the factory specification by more than 10%, or it will fail annual inspections. It's recommended to use branded accessories and check for GB standard labels. After modifications, remember to update the vehicle's information at the DMV for legality and to extend the car's lifespan.
