If the clear coat on the top of the car starts to peel off, do you think I have to sand it down to the primer and repaint? Is there a way just to take the clear coat off, then spray a little new paint on, and then clear coat again?
You need to get really really fine grit sandpaper (like 600, talk to the guys at a carquest or other auto paint store for sure). This stuff will take off just the clearcoat and allow you to get the damaged area re-cleared. A quart of clear is only like $35 and that should be plenty. Hope this helps.
I would suggest taking it to a paint shop and having them paint the roof between the raingutters. Should be able to find someone to do it for around $150. Sanding it with 600 grit would take a while to feather the paint (smooth when you run your hand over the section). If you can feel the edge between the clear and where it chipped off, you will see it through the new paint. Sanding it will take off the clear where the clear is there, but where it chipped off, you’re sanding the paint itself. As far as doing it yourself, It would cost you quite a bit more. You will need primer, base coat, and clear coat. Keep in mind these products will either need a reducer and/or catalyst as well. Also some of these products are sold by the quart or more. Oh, you will need a paint gun and compressor too.