One of the unsung heroes of the auto world, C. Harold Wills designed the Model T when he worked as Henry Ford's right-hand man. Later, he founded his own company to produce the legendary Wills Sainte Claire. Every endeavor displayed his trademark inventiveness, from the development of the overhead cam engine to the toboggan run on the roof of his house. He used his money to create one of the first worker model cities at Marysville,...