I'm picking apart the PSDs right now.. It could have definitely been done in Photoshop... In fact, looking at the PSDs I can do it..
Everything is on a seperate layer...
I would guess it was done in this order: First they extracted the car from the background and pasted it back in place. Secondly they drew outlines of the car and details on a seperate layers.. Highlights, Shadows etc... etc..
I messed around with the colors a bit to show what I'm talking about...
