A lot of these cars look quite rubbish when you see them close up. If you ever get the chance to visit 'Cars Of The Stars' you should go. It's really interesting. They have far more cars than they can display at any one time so they rotate them. I've been a few times so I've seen lots of famous cars. I also visited the James Bond exhibition in Edinburgh before it closed.
http://www.carsofthestars.com/
The 'Back To The Future' Delorian is cool, close up you can see that it's lots of ordinary bits and pieces just bolted to it. Close up you can see that the rust on Del Trotter's van is painted on, as it would have to be as the van is fibreglass! ;0)
I really like the 'Mad Max' Interceptor. I just read on the 'Cars Of The Stars' website that a movie executive saw the customised car sitting on someone's driveway and bought it for use in the film. They didn't change anything on it, that's exactly the way it was when they bought it!
I think my favourite is 'The Munster's' Koach. What a brilliant car.