This is a list I just came up with of the first things that popped up in my mind. Add, discuss, amend as you may see fit.
10. I Am Legend - Ford Mustang:
The most benign of this list -hence it's number 10. In a post-apocalyptic New York City where a virus has turned most of humanity into ravenous CGI zombie-like creatures a man immune to the disease roams the ruins of civilization. By day he hunts down his dinner along with his companion dog and occasionally captures a zombie and hauls it home to work on a cure for the virus. The movie opens with establishing shots of New York City and Will Smith's character hauling-ass around the ruins in a Ford Mustang. A fun car, sure, but sort of impractical for survival purposes in such a nightmarish situation, certainly Will Smith's character figured this out as he spends the rest of the movie driving around in a far more practical SUV. The tearing ass, glamor shots, 'Stang Porn and such of Mustang in the opening moments? Just for product placement.