How to Design Cars Like a Pro by Tony Lewin; a great book on auto design. Gives a "day in the life of a designer", and guides to creating your own design step by step. It uses real concepts to illustrate as well.
And Doug Dubosque has a great series out for beginners, some of which are very informative.
Learn to Draw in 3-D, which is a step by step to learning accurate perspective on landscapes, cars, and other things.
Learn to Draw Cars, which is a step by step on drawing cars in 2D and 3D, shading, drawing wheels, and creating your own cars.