A couple of digital doodles on my computer using Groboto3D, ArtRage & Photoshop....
Retro Red Exotic - An exotic sportscar of the future borrowing some styling from cars of the late 1950's and early 1960's.
Grobo-car - My vision of a hot rod of the future powered by a clean energy source and has dual wheels in the rear, making it a 6 wheel vehicle.
I created both cars in Groboto which is a 3D modeling application. I then brought the base render into Artrage 4.5 where I painted over the image and applied a gradient. I used Photoshop for color correction and applied a texture to the background and added some noise to the car.