As I remember, I painted my old car with pink Krylon. I think it came from Wal-Mart (I didn't have much of a choice). It held up OK. I'd certainly recommend cleaning it up, sanding it, priming it, sanding it again, and then painting it. Part of the problem you run into is that rattle cans give you a lot of paint dust on the surface, so you want to try to eliminate that as much as you can.

One advantage is that if you chip the paint, you can always just paint over it.