What is the Legal Modification Range for Car Spoilers?
4 Answers
Do not alter the length and width of the vehicle. Exterior modifications: Replacement of vehicle exterior logos, colors, decals, installation of sunroofs, addition of front and rear bumpers, roof racks, rear spoilers, and upgrades to tires, rims, and chassis. Interior modifications: Modification of interior facilities, including steering wheels, replacement of sport seats, addition of instrument equipment, and sound-deadening materials. Power system upgrades: Modification of exhaust pipes, turbochargers, etc., utilizing the gap between the engine's design power and actual power to increase instantaneous displacement. Registration: If a vehicle owner wishes to change the body color, replace the engine, or alter the body or frame, they can proceed with the changes first and then submit an application for modification registration to the vehicle management office within 10 days.
I've specifically researched traffic regulations regarding car spoiler modifications. According to national standards, the spoiler width must not exceed the vehicle's body width, the height must stay under 30cm, and it absolutely cannot obstruct the license plate or rearview mirror visibility. After modification, you must register the changes at the DMV and retake the vehicle license photo, otherwise it will definitely fail the annual inspection. One common pitfall is using overly sharp materials - if traffic police find metal spikes or sharp edges, it's immediately classified as illegal modification. My installed spoiler stays within 1.5 times the original car dimensions, and I submitted design drawings for registration in advance - it's passed two annual inspections without issues. Also, I'd recommend avoiding overly flashy reflective materials as excessive nighttime glare could be deemed hazardous to following vehicles.
I've learned my lesson from modifying rear wings, so I know exactly where the red lines are. There are three core rules: don't exceed the original car width in size, keep the height under 30 centimeters, and avoid overly flashy colors. Modification shops often trick people by saying small wings don't require registration, but actually any alteration to the body shape needs to be registered, otherwise you'll get points deducted and fined if caught. Last time, my friend installed a carbon fiber wing with qualified materials, but didn't notice the edges were too sharp and got fined 500 for endangering road safety. Another key point is not to install lighting elements - some people like adding LED strips, but this counts as altering the electrical structure and will definitely be checked by traffic police. If you really must modify, choose safety-designed wings with rubberized soft edges at the bottom for maximum security.
When modifying a rear wing, pay attention to three key aspects: the width should not exceed the car body, the height should be no more than the thickness of a book, and the design should not be too flashy. For example, large rear wings like those on sports cars are definitely not allowed unless you own a factory performance version. Before making modifications, I specifically went to the vehicle management office to inquire, and the staff mentioned they focus on three main checks: whether it obstructs the license plate, affects rear window visibility, or alters the vehicle's identifying characteristics. Currently, about 80% of the universal modification parts on Taobao are non-compliant, so it's recommended to order from professional manufacturers. Remember to file the modification with the authorities within ten days after installation, bringing the vehicle registration certificate—the new driving license can be issued the same day after taking photos. If stopped by traffic police for modification checks while driving, the first thing to do is show them the modification record.
