Some members on Jalopnik found a nice online customizer, so I thought I'd share it here. It's got a number of real models, and even wheels, body parts, etc. It's like all the world's car configurators rolled into one with some aftermarket parts.
Anyways, play around with it and post your creations here. :D
I'll start with my Audi A4. :)
http://i737.photobucket.com/albums/xx20/ScoobSTi/1_zpsd6cbb5cc.png
http://i737.photobucket.com/albums/xx20/ScoobSTi/2_zpsad2c7e43.png
http://i737.photobucket.com/albums/xx20/ScoobSTi/3_zps36eb7448.png