Tony Stark's car from the Iron Man movies. Not really the Batmobile, but still cool.
I saw it on a feature by National Geographic about Megafactories. Audi was their featured factory then and they showed how they made the R8, and they mentioned how the R8 changed the script in the Iron Man movie. Here's the details of it from IMDB.com:
"During the final battle, there was originally going to be a sequence where Tony, in the Iron Man suit, drives an Audi R8 that would crash into Iron Monger's legs then flip over, after which Iron Man would split the car in half and jump out. However, the Audi R8 was so well-built that it refused to flip despite repeated crashes and the roof wouldn't split the way the Director wanted it to because the car's frame was so tough. As a result, the whole final fight sequence was re-written. The filmmakers were so impressed by the toughness of the car that it was decided that the convertible version was to be featured in the sequel."