I find it interesting that the 343M-GC and 433M wheels are narrower at the rears than the coupe.
F12 M6 343M wheels:
http://www.realoem.com/bmw/showparts...43&hg=36&fg=15
Also, 9250 for CCB's with sliding single piston binders in the rear. You would think BMW would throw in a fixed 2-pot at least for close to 10K.