I don't know how anyone can paint a body without using a primer first. I have never seen a body that did not need some kind of body work. Molding seams and sink marks are just about on every kit I ever built. If you do body work you need to prime. There maybe paints that will cover without primer if you don't do any putty work or sanding but you won't get as good a finished product. This is just one guys opinion.