Mystery car spotted during Transformers 2 filming

To all of you Autoblog sleuths out there, it's time to go to work. The silver car in the picture above was spotted on the set of Transfomers 2 filming in Pennsylvania. The wheels (cartoonishly large out back) and lines, and the fact that GM is a major player in the film, would seem to suggest it's some sort of GM product or concept -- although not the Corvette ZR-1, as some have claimed. It's also got the same concept mirrors that GM loves to use and kind of looks like Bumblebee's evil Decepticon twin. The shooter also said that the car has scissor doors like a Lamborghini. Follow the link to see more pictures from the filming, and let us know what you think the mystery car is.