I have just learned a ton about rendering through tutorials and it sounds to me like markers + pastel + gouache for highlights and lowlights sounds like the best way to make a car as realistic on a piece of paper as it is in real life. The chalk is often used for high contrast, smooth blending and a good sense of sky reflection. The markers should only be used for the brilliant actual color of the car and gouache should be used sparingly in order to show the very deep reflectiveness (usually for the little white glimmers you see from direct light sources. Now that I have figured out the design tools I'll be using, all I need to do now is figure out my design and then this project is going to start looking awesome. At this stage all I have is the Citroen GT for basic body design (its big and bad yet still seems to maintain a sporty look). Im still open to ideas.