The BMW M8 is rumored to have the same platform as The BMW i8 (09/2013). Photo: BMW. 

It's rumored to have 640 to 670 horsepower, thanks to an upgraded version of the M5's direct-injected 4.4-liter twin-turbo V8. It can go 0-62 in about 3 seconds, is made from materials such as carbon fiber and titanium -- which could give it the best power-to-weight ratio of any BMW street car -- and is the fir