Here are a couple of his WIP tests on detailed car model.
The first one was done in one of the earliest CentiLeo. The last picture was done with 0.452 for Max (1 minute for 2000x2000) on one GTX Titan straight out of the raw render.
So, he tried to make carpaint (see second picture) with some image of normal map flakes. I think we should make some procedural flakes shader for such tasks