We’ve already seen prototypes of the upcoming McLaren P11, but the anticipated supercar is now going back to the drawing board for a redesign by new styling chief Frank Stephenson. AutoCar sources say that Stephenson will be joining McLaren later this year after he completes is term at Fiat.The former BMW, Mini and Ferrari designer will join McLaren and will first take on the P11 followed by a family of supercars that McLaren wants to put out in 2009. Sources are saying that most of the engineering has been completed but design is open.The new P11 will be very different from what we’ve been seeing but power still said to come from a...