When General Motors rolled out its “skateboard” vision for a fuel cell car at the 2002 Detroit auto show in January, there was buzz, and there was a big question. The skateboard concept, called Auto-nomy, was the product of GM’s Design and Technology Fusion Group, and it radically reordered automobile physiology: Fuel cells, hydrogen, motor, and brakes were all crammed into a 15-foot-long, 6-inch-thick chassis onto which modular car bodies could be snapped. Drive-by-wire controls would plug into the skateboard’s computer brain through a docking port.

With all of the important mechanicals belowdecks, the car could be configured for maximum space and utility. An owner could trade in a sedan for a pickup by simply having the new body snapped onto his skateboard. Pictures of the “skateboard” here.