Before there was NASCAR, there was box car. Soap box derbies, at the peak of their popularity in the 1950s, provided all-American kids with an opportunity to mix engineering ingenuity with the need for speed. Today, enthusiastic adults raised on Mario Kart are reviving this wholesome tradition on the slopes of Mt. Tabor in Portland, Oregon. It's art on wheels, speeding down the side of a dormant volcano.