The Transformers are an alien race of robots which can transform into any mechanical object. They came to earth to look for the all spark. Lead by Optimus Prime, they brang their war with the Decepticons to Earth. With the help of Sam Witwhicy they head to the Hoover Dam where it has been hidden since the 50's.
When we first meet Sam, he buys a 1976 Chevy Camaro. This turns out to be Bumblebee, an Autobot. He is the only classic car in this film that has a major role. Bumblee later transforms into a new Chevy Camaro SS when Sam calls him a useless piece of junk.