The crumpled paint on the lower right corner of the back door of BMW Five Series is damaged and needs to be repaired. You can choose the following methods:

1. Partial repair: If only a small part of the paint surface is damaged, you can buy nail polish with the same color number and apply it to a small area of the damaged paint surface, or spray it with the same color paint and reusable tools according to the instructions.

2. Global maintenance: If the paint of the whole door is seriously damaged, it is recommended to go to a repair shop authorized by BMW for comprehensive maintenance, and the cost may exceed 3,000 yuan.

In addition, if the damaged part is exposed to the primer, it must be repaired in time, otherwise the metal part will be easily oxidized and rusted. You can consider using it when repairing.