Itala 35/45hp: From the 2007 series Peking to Paris (which doesn't seem to have an IMDB page, let alone a page here). A group of people retraced the 1907 Peking to Paris rally using the same model cars used in the original race. It's a great series and I'd like to see all the cars they used added, but the Itala is my favorite.

Red MkII Supra: Background car in one episode of Arrested Development, I forget which now.

Stealth Bomber car: They had a bit about this in one old episode of Extreme Machines. I think it's probably the same one they used in Knight Rider 2010, but I'd like to see it added just to be sure.