If you have rust the paint job will cost a lot more since they have to cut and weld new metal. They also have to check if there is any rust inside the car in the outside's effective area. For example, I have rust in my left rear wheel well and if I went to get it repainted they would take out my rear seats and check for rust. It's something I could check for but 1) Im a noob and don't know how to take out my rear seats, and 2) Im lazy.