Officially it?s only a concept, but there?s no doubt that project XG10 -- or the 918 Spyder concept -- will pave the way for the next Porsche supercar. And what a supercar it is going to be: in addition to the normally aspirated, high-revving, 3.4-liter V-8 good for 500 hp, the striking 918 Spyder has three electric motors onboard that add another 218 hp to the tally. Says Wolfgang D?rheimer, board member in charge of R&D: ?This car can lap the N?rburgring faster than the Carrera GT. At the same time, it averages 95 mpg when driven gently. Are we going to build it? We will definitely bring some blank sales contracts to the Geneva show, but it?s too early to talk pricing, production volumes, and timing.?