Why is Car Modification Illegal?

[LilyDella]

Laws and regulations impose restrictions on car modifications. The vehicle model, engine model, and chassis number cannot be altered, and the body structure must not be compromised. If the car's color is changed, or the engine, body, or chassis is replaced, the vehicle must be inspected. Additionally, replacing the engine, body, or chassis requires submitting a valid motor vehicle safety inspection certificate. Decals or stickers must not cover more than 30% of the total body area. However, there are cases where car modifications are not illegal. Changing the car's color: It is permissible to change the car's color, but avoid using camouflage patterns, fire engine red, emergency vehicle yellow, or law enforcement's white-and-blue scheme. Most importantly, remember to complete the modification registration at the vehicle management office within ten days and obtain a new driving license. For those who wish to add decals, ensure the coverage does not exceed 30% of the car's body area. Important notes: In principle, modifications are allowed as long as they do not affect driving safety. However, seats cannot be removed, the interior structure must remain unchanged, and any structural features registered with the vehicle management office must not be altered without authorization.

[Braylen]

Having worked as a car mechanic for over a decade, I've noticed many young people don't understand why there are restrictions on modifications. The primary concern is safety. For instance, randomly altering the suspension can disrupt the factory tuning, making the car prone to losing control during emergency lane changes. Last time, a lowered Honda Civic came into the shop and scraped its oil pan clean over a speed bump. Then there are those who install overly bright headlights, blinding oncoming drivers. Regulations are even stricter about engine and exhaust modifications. Flashing the ECU might cause emissions to exceed standards, and excessively loud exhaust systems can result in fines. Actually, the regulations do allow some leeway: you can change to wheels of the same size or modify the body color with proper documentation. Just don't touch the powertrain or chassis structure.

[HarperRose]

A friend of mine learned the hard way with car modifications. After an accident caused by illegal modifications, the insurance company outright refused to cover the damages, and the court ruled him fully at fault. Article 16 of the Traffic Law clearly states: unauthorized alterations to registered structures are illegal. What the modification community often refers to as 'DMV registration' actually only accepts changes like interior modifications or roof racks. At a gathering once, I saw someone welding a roll cage—this might look professional but actually compromises the car's structural integrity, potentially causing airbag failure in a real collision. Most critically, under new environmental regulations, modifying the exhaust on a China VI vehicle will definitely exceed emissions standards, making it impossible to pass the annual inspection. Those viral modification videos never mention these consequences.

[LaIris]

We track day veterans know the legal boundaries best. Illegal modifications are divided into three levels: the most severe is altering the engine number or chassis number, which is outright illegal; next is modifying the turbocharger or exhaust catalytic converter, which will definitely fail the annual inspection; the lightest is changing body kits or wraps, but exceeding 30% without registration will still get you fined. Car enthusiasts should understand: factory models undergo millions of kilometers of testing, while your aftermarket parts haven't even had crash tests. Last week, I witnessed a heavily modified Fit speeding on the highway when suddenly its hood latch failed and flipped up, smashing the windshield. True car lovers should modify their vehicles at professional race tracks - public roads aren't drag strips.