Yes, traffic police will regulate LED displays on car rear windows. If there are violations or illegal modifications, they will be investigated and punished. Specifically:
I. Suspected Violations: According to traffic regulations, the rear window of a motor vehicle must not be largely obstructed; generally, more than one-third of the area should be covered. If the LED display obstructs the driver's view, affects normal driving, changes the vehicle's main color, or the advertising area exceeds the prescribed limit, it is considered a violation. For example, if the LED screen displays overly glaring content or flickers too frequently, it may interfere with the view of drivers behind; or if the screen area is too large, obstructing the rear window view and preventing the driver from observing road conditions behind through the rearview mirror, it may be considered by traffic police as affecting safe driving and will be investigated and punished according to law.
II. Consequences of Illegal Modifications: Vehicle modifications must comply with national regulations and be registered with the local vehicle management office. Unregistered modifications, especially those affecting the vehicle's appearance or safety performance, are generally considered illegal modifications. Installing an LED screen on the rear window of a car changes the original appearance and structure of the vehicle; if it has not been registered and approved by the vehicle management office, it is considered an illegal modification. According to relevant regulations, unauthorized vehicle modifications discovered by traffic police will result in a 6-point deduction and a fine of 500 to 1000 yuan. For example, a man in Changchun installed an LED screen on the rear window of his car, displaying the text "Changchun's Number One Scumbag [Name]". Because the content was inappropriate and not registered, he was investigated and punished by traffic police, ordered to remove the screen, and fined 200 yuan.
III. Legal Modification Procedures If a vehicle owner genuinely needs to install special equipment such as an LED screen, they should first submit a modification application to the local vehicle management office, providing relevant supporting documents and a modification plan. Modification can only proceed after the vehicle management office approves the application. After modification, the owner must ensure that the modified vehicle meets national safety technical standards and does not affect the vehicle's normal driving and safety performance. For example, the brightness, size, and installation location of the LED display screen must comply with regulations and must not obstruct the rear window view or interfere with the driving of other vehicles.
