I had been looking to replace my factory front rotors and was considering picking them up from www.racingbrake.com
but the back breaking cost has kept me from pulling the trigger thus far. I have heard nothing but rave reviews (from the hack) and from a few others that have been running the rotors on their cars (not MZ4's.) I figure if I could get 3 or 4 years out of them it would definitely be worth the price of admission.
Forum member BTM pointed out to me that it's the same size as the 335i blanks (which should fit.) If they work that's a huge cost savings even over OEM rotors!
Has anybody tried this or am I going to be the first (after a bit more research of course.)