completely wrong offset, with o.e.m bmw e92 m3 alloys you'll get biblical rub.
hell even the CSLs upfront arent the correct offset for the z4m, hence thats why they sit quite retracted in, infact the are more sunken on the front the stock z4m, many correct that with a spacer.
ideal wheel offsets for the z4m are front et32-et35, this is nice and flush with the fender line, with a little cameber (which the z4m needs anyway) they'll be tucked in slightly.. the rear looks PERFECT with et 24-27.
hope this helps alittle.
byron