Arguably, the top concept at the recent Geneva Motor Show, the Porsche 918 Spyder takes the plug in hybrid idea to new heights.? With styling evolving from the Carrera GT the 3,300-pound carbon-fiber body Spyder is powered by a mid-mounted 500-hp, gas V-8 engine and a pair of electric motors adding an additional 218-hp. The all-wheel drive two-seater accelerates from 0 to 62 mph in just 3.2 seconds and has a top speed of 198 mph.? Porsche chairman Michael Macht answered questions about possible production by saying that Porsche has never shown a concept car that didn?t eventually get put into production.