to be honest, you might drop by the 3ds max forum. In other programs (I only know Wings, and to a limited extent, Blender), you select faces, and apply colors, or differentiate areas that will take a given texture.
Once you've determined that, you UVMap it..I'm on real shaky ground with UVMapping (done it twice, now..;), and can apply jpg textures to the given area. There's also a UVMapping forum here, and tutorials galore, on how to do it right.
Since it's a car, you could probably get by by setting textures for the body, and use the color button (or whatever that paint can thang is called) to apply 'car colors' to it.
good luck, Jim..

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)