I've tried understanding this stuff for years in max. I never did get too far despite spending hundreds, if not thousands of hours in that program. You're using UVUnwrap for the masking and paint separation (texture #17) -- ??? I wish I could wrap my head around this.
Not really - since most of my paints are a base coat - clear coat type, I typically use a shellac material with two Vray materials of differing specular and reflective qualities to emulate a metallic base coat with broad highlights and lo reflectivity and then a gloss coat that his quite reflective with strong highlights.
The Vray carpaint mat is a pretty weird beast. I'm not always happy with the results. The flakes never seem to cooperate the way I think they should.
Ah right cool. Yeah ive just been using the VrayCarPaint but like you say, its not always the best. Ill have to have a play around with the shellac method, ive seen a few examples of it lying about, i just need to devote more time to the materials as there just as important as the model in a sense!