You can't modify the appearance of a car without permission, because it will be illegal if it is inconsistent with the driving license after modification, and you must go to the vehicle management office for filing.

after modifying the vehicle, you need to go to the vehicle management office for filing, and at the same time, you need to be examined. If the examination result of the vehicle management office is unqualified, you must change it back to its original appearance. If the results of the DMV review are qualified, then you need to change your vehicle information. In this case, the bumpers at the front and rear ends of the car refer to safety devices used to absorb and mitigate external impact, protect the body and protect the safety of the body and occupants. At the same time, it has decorative function.

according to article 1 of the "regulations on motor vehicle registration" issued by the Ministry of public security, if a registered motor vehicle has any of the following circumstances, the owner of the motor vehicle shall apply to dmv for change of registration: (1) changing the body color; (2) replacing the engine.

(3) replacing the car body or frame; (4) Replacing the whole vehicle due to quality problems; (five) the nature of the use of operating motor vehicles to non-operating motor vehicles or non-operating motor vehicles to operating motor vehicles has changed; (6) The domicile of the motor vehicle owner has moved out or moved into the jurisdiction of dmv. " Replacing the bumper is not within the scope of change requirements.

however, if the replaced bumper is exaggerated in shape, the surface area is large and the color changes, you need to consult the traffic control department specifically. Because it is possible to touch the article "(1) changing the color of the car body". You don't need to change your driving license.