What are the regulations for car modifications?

[FelixRose]

Specific regulations for car modifications are as follows: 1. Prohibited modifications: Modifications that affect vehicle safety, such as the braking system, power system, and suspension system, are not allowed. In case of a serious accident causing irreparable damage, re-registration and approval with the vehicle management office are required. 2. Modification restrictions: According to laws and regulations, the vehicle model, engine model, and frame number cannot be modified, and the body structure must not be altered. Vehicles that change color, replace the engine, body, or frame must undergo inspection. For replacing the engine, body, or frame, a valid motor vehicle safety technical inspection certificate must be submitted. Additionally, the area of car stickers must not exceed 30% of the total body area.

[StArya]

Car modifications can't be done casually, as the state regulates them quite strictly. You can change the body color but must register it with authorities. Wheel rim sizes must remain the same as the factory specifications - no upsizing allowed. If you secretly modify the suspension to lower the chassis, traffic police will issue penalty points and fines upon discovery. The most critical restrictions involve the engine and exhaust systems - unauthorized turbocharger modifications or loud "street-racing" exhausts will definitely fail annual inspections. My neighbor installed a cool-looking spoiler last year, only to be pulled over and ordered to restore it to stock, wasting thousands. Interior modifications are relatively more lenient, as long as you don't remove seats to install sleeping berths.

[LaLena]

The biggest concern with modifications is safety. I've seen cases where people installed substandard brake discs and ended up rear-ending others. National regulations stipulate that no modifications should compromise vehicle safety performance. For example, excessively enlarging the steering wheel size to the point of affecting steering responsiveness is strictly prohibited. Lighting modifications are particularly prone to violations—installing glaring blue lights or strobe lights can result in severe fines. It's advisable to consult the 'Motor Vehicle Registration Regulations' before starting any modifications. Have a professional modification shop draft a blueprint plan and submit it to the vehicle management office for approval, to avoid failing the annual inspection later and having to dismantle the modifications.

[Parra]

Modifying cars requires some know-how to do it right. Keep body wraps under 30%, and any color changes must be registered within 10 days. You can swap wheel designs freely but keep the original size - I failed my annual inspection after upgrading from stock 16-inch to 18-inch wheels. Exhaust tip modifications are the trickiest, those loud street-racing exhaust notes will get you pulled over immediately. I never touch electrical systems when modifying - the fire risk is too high. For beginners, start small with roof racks or steering wheel covers. Leather seat upgrades are the safest interior mod.

[DelJude]

Having worked in the auto repair industry for seven or eight years, I've seen too many car owners stumble with modifications. The most common issue is lighting upgrades—halogen to LED conversions must include lenses to avoid severe glare. For off-road vehicles, remember not to raise the suspension more than 3 cm, and lowering the chassis shouldn't go below 5 cm; exceeding these limits will make it fail inspection. Engine ECU tuning might pass checks in the south, but northern annual inspections will expose it, requiring a revert. For major modifications, it's wise to keep the original parts, in case they're needed for inspection reinstatement.

[OIvan]

Just went through my car's third modified vehicle annual inspection, and I've learned a lot. There are clear red lines in car modification: never alter the body structure - converting to a convertible by removing B-pillars is outright illegal. Additional bumpers must be registered within 10 days and shouldn't exceed 5cm beyond the body width. Last week, I had to remove the black roof wrap from my SUV to pass inspection - any tint film with less than 70% light transmittance violates regulations. Always ensure modification parts have certification marks; avoid uncertified parts from Taobao without 3C approval, or inspectors will make you redo everything immediately.