Car stickers are not illegal. As long as the area does not exceed 30%, it is allowed, and it is necessary to go to the vehicle management office for filing. You can stick stickers on the car body, but you must abide by the relevant regulations. Advertising car stickers are not allowed. Car stickers are based on the premise of not affecting others' driving. The traffic police will punish you if you stick it on the window or other places that obviously block the line of sight or block the license plate.

The process of vehicle change procedures is:

1. Drive to the transfer hall, park in the car inspection area, and wait for the police to check the car. (If the vehicle is found to be in violation of regulations, the traffic accident has not been closed, and the vehicle mortgage has not been cancelled, it is necessary to restore the vehicle state to normal first);

2. Print invoices for used car transactions in the trading hall and pay transfer fees;

3. Number in the trading hall, waiting for signature confirmation;

4. After the buyer signs and confirms, go to the hall number selector to select a new number plate;

5. Obtain the new procedures (registration certificate, driving license) and number plate of the transfer vehicle, and complete all the transfer procedures.

Legal basis: Article 6 of the Regulations for the Implementation of the Road Traffic Safety Law of the People's Republic of China.

If a registered motor vehicle is under any of the following circumstances, the owner of the motor vehicle shall apply to the traffic management department of the public security organ that registered the motor vehicle for change of registration:

(1) Changing the body color of a motor vehicle;

(2) Replace the engine;

(3) replace the car body or frame;

(four) due to quality problems, the manufacturer replaces the whole vehicle;

(five) the operating motor vehicle is changed into a non-operating motor vehicle or a non-operating motor vehicle is changed into an operating motor vehicle;

(six) the motor vehicle owner's residence moved out or moved into the area under the jurisdiction of the traffic management department of the public security organ.

To apply for registration of motor vehicle change, the following documents and vouchers shall be submitted, and the motor vehicle shall be submitted for inspection under any of the circumstances mentioned in Items (1), (2), (3), (4) and (5) of the preceding paragraph; In the case of items (2) and (3) of the preceding paragraph, a certificate of motor vehicle safety technical inspection shall also be submitted:

(a) the identity certificate of the owner of the motor vehicle;

(2) Motor vehicle registration certificate;

(3) Motor vehicle driver's license.

Where the domicile of the motor vehicle owner changes within the jurisdiction of the traffic administrative department of the public security organ, or the name (unit name) and contact information of the motor vehicle owner change, it shall be filed with the traffic administrative department of the public security organ where the motor vehicle is registered.