The first pic to me looks like it was A) taken from a rig at a very low speed, probably 5 or 10mph rolling on a longer exposure. B) The smoke looks totally pshopped in.

The second pic looks "all natural" except it was possibly taken at a slow rolling speed of a few mph. But the background etc doesn't look pasted in.

To me, someone w/ about 10 years experience at photographing cars and whatnot, the second pic is way, way more impressive. It's an awesome shot.