High-tech highlights include a fully-retractable, self-covering hardtop, conceptually similar to the smaller SLK's. Press one button, and the SL500 goes from fully-enclosed coupe to wide-open roadster in 16 seconds. Fascinating, purposeful stuff, but the real trick is the world's first production-car use of a fully electronic braking system. A conventional pedal controls a computer, which in turn manages four fast-acting valves that apply braking force to the wheels. Engine 5.0-liter V-8, 302 hp, SOHC, 3 valves/cyl.