Dog nail scratches

My dog hates cars. So she doesn't jump in the car, she looks at it, looks at me like "do I really have to go in this thing", then slowly, very slowly, gets in the back seat. Today I noticed lots of nail scratches on the bottom of the door. What is the best thing to use to remove scratches? And how can I tell my dog the Mustang is the best thing on earth and that she should jump in it?