Your body/paint shop can explain it a whole lot better, but for looks and ease of maintanince, I'd go with base coat/clear coat. My Chally has two coats of some type of primer (forget the name) that is ultra tough, in fact the body shop guy said you'd have either use a disc grinder or sandblaster to remove it (?), it then has three coats of base coat and then two coats of clear coat. Oh, I forgot the coat of fine blue pearl before the clear coat. Some guys want three or four coats of clear coat for that real "deep" effect, especially on dark shades, but my paint guy said you run the risk of cracking with too many layers of clear coat...?