I would imagine it would be fine, as long as you make sure the screw holes are covered so water does not get into them, as for base coat colors you can use anything really but remember it will have an effect on any other colors, Im doing a GMC swirld and have given the body a green base coat as I dont want any white showing through if paint doesnt stick. The green base wont affeft the black as you can imagine. but it you were to do a dna kinda thing then you couldnt really put a red base on it because the red would discolor the yellows and other colors. This has been talked about elsewhere, Its really up to you, I would just do a lot of testing to see how differant base colors affect the top colors.