I am a fan of 275/30 to minimize the stagger but I wouldn't go that wide with anything narrower than a 9.5" front wheel.
'08 E90 M3 - Alpine White - Sold
'13 E92 M3 - Silverstone II - Sold
'13 E92 M3 - Alpine White - BBS E88, JRZ, Akrapovic, AP Racing
'04 E46 M3 - Jet Black - BBS E88, KW Clubsports, Brembo BBK, SuperSprint Exhaust, Recaro - FOR SALE