Photos: Concept cars keep on truckin'

Concept cars arrived in all shapes and sizes at the Chicago Auto Show this week. Ford's F-250 Super Chief is designed to run on three different types of fuel--hydrogen, E85 ethanol or gasoline--and travel 500 miles per fill-up. Plus, the roof is made of glass, "bisected," according to the press material for the show, "by a leather-wrapped grid of American walnut."