"Ten years ago, I received a letter from a man named Bob Shotwell who lived in a small town in Minnesota. He knew that I liked old cars from watching me on television. And he wanted to give me one. He recalled that he asked his father for a car as he was about to graduate from high school in the early 1930s. But his dad replied that if he wanted a car, he should build one. So, 17-year-old Bob scrounged parts and made his own car. It was a little three-wheeled coupe powered by a 77.2-cu.-in. four-cylinder 1931 Indian...