Guys, you should check out:
http://www.allcarschat.com/
Not only is there a discussion forum for all makes and models of cars, but there's also a photoshop section, where you are asked to modify images and or create your own concepts.
There are monthly contests. This month is: Design vehicles for Lincoln/Mercury.
(No prizes, just for fun of course)
Check it out:
ALL CARS CHAT