I can't believe all the talk about R-tires. Sportauto has tested several cars on streetlegal R-tires so the new M3 isn't alone. Audis, Benzes, porsches, ferrari to name a few are cars being tested with streetlegal R-tires.
Why is this a problem now?
If others can "cheat" then so can bmw. And I dont get the fear that M3 is going to be faster than a 911 around N-ring. Noone is going to cancel or sell their 911's becuase of this.