i am so into modeling now

I'm in! looking to buy another car model, maybe for Christmas for myself or the older kid. I wanna use real world rust colored paint and lots of flats on the suspension. Make that warped body car a demo derby car! Hood headers, big *** bumpers, striped tires! Question, how do you shoot clear over paint so it doesnt melt the paint? Everytime I try and clearcoat something, it just ruins the paint under it? Not dry enough?