Is it a modification to crown the tail?

Of course, the tail mark of a car can be changed. Changing the letter symbol is not a modification. This behavior is like putting your favorite slogan or pattern on your car. Illegal modification is indeed prohibited in China, but this modified trailer is not modified at all, nor is it illegal.

Although there are restrictions on modification in China at present, it doesn't mean that it can't be changed. Now "changing oil to gas" is still open in China.