Haha, it is a decade we get monthly rumors of supercar coming. And why should BMW make a supercar for the 100th anniversary? They didn't do any M3 CSL for celebration 40 years M. A TC 4.4l V8 is crap for a supercar. It is neither this nor that. And mid-rear engine too is crap for a BMW. There is enough choice among the mid-rear engined cars.
I don't get these constant rumors of M supercar, unless M has been building the car for a decade already, like McLaren the MP4-12C and Lexus the LFA. If true this BMW supercar would blow everything out of the water, including all Porsches, the Lexus LFA, the Ferrari F70, the McLaren P1 and the Paganis. But I doubt.