What to do if a piece of paint is scratched on the car door?

[KendraFitz]

If a piece of paint is scratched on the car door and it's just a small area with the primer still intact, it's recommended not to repair it. If the primer is gone, it's advisable to get it repaired, otherwise, it may lead to rust on the door. Generally, minor scratches only affect the clear coat, which can be removed with simple polishing. Deeper scratches that reach the base coat require touch-up paint for removal. If the scratch damages the primer surfacer, it can cause rust on the car's steel body. The car's paint consists of four layers, from the inside out: the electrocoat primer, primer surfacer, base coat, and clear coat.