This book is about the history of product variety in the US automotive industry from the black Ford-T to hot-rodders and easy-riders up to latest trends. It focuses on the dual structure of automotive industry in the United States: on one hand, relatively few and large companies producing cars that apparently achieve a degree of market power through product differentiation, and on the other hand, a relatively small niche market with distinct and smaller producers offering specialty equipment to enhance the performance, appearance, and handling of vehicles. The book presents novel results from an in-depth study with implications for both economic theory and the management of product variety.