Update 2006.07.04: This faking method has now been made redundant with the material node system in Blender 2.42. Check out my new node-based method, with image, movie, description and .blend file.
Here’s a video tutorial about creating a car paint shader in Blender, in time for the Blender community F1 challenge. I tried to give a thorough explanation of the theory behind it, rather than just posting the .blend file on it’s own.
A Car paint (12MB MPEG4) A / A