It wouldn't hurt to throw them on the M3 when it arrives just to see how they turn out. I agree with the others. They'd look a whole lot better on the M6 with a drop. Keep that in mind for the M3 as wheels always look better without the fender gap.
2016 Agate Grey GT4 PCCB LWB PCM
2013 Mineral White e92 M3 DCT ZCP ZPP