RE: Retro Cars, Chevy HHR, etc.
I agree about the 50s thing. Although they more or less did that with the thunderbird which wasn't very successful. The 300c also has some slight 50s elements too it. There was also a very cool custom car you can order, I think it was based on a combination of old chevys. If I find it I'll post it. Not cheap but great looking.
Unfortunately the way things are going all the progress towards nice looking cars we've made will end with a return to 90s blah.