Photos: When GM's designs ruled the road

The 1959 Cadillac Cyclone concept had a number of futuristic tech elements, according to GM, including a radar device and, in those dual nose cones, proximity sensors, all of which would warn the driver of objects in the car's path. The doors slid out and back, just like the side doors on many of today's minivans, and the clear plastic canopy top, hinged at the rear, rose automatically when a door opened. You didn't have to open it up to talk to folks outside, though; for that there was an intercom system. Under the hood was a 325-horsepower engine.