Re the colour .... I found on a couple of cars were I couldnt get the right shade from the colour cell, (for the yellow/green on the focus front for example) that overlaying the same shape with a copy in a different colour and playing with transparency to mix the shade worked, but you already know that and it doesn't work so well if you have overlays in the shapes, which I imagine there are plenty of in KP's trousers.
I had been looking for a good unlocked red bull logo/text to do another car with, so if you have one, or know were I can get one, that would be handy, its beyond my patience and abilities