Thank you for your replies..
I definately don't want to roll the fenders or run excessive camber. I drive allot of miles and don't want to kill the rear tires too early. I sent an email to the seller regarding the rear offset and they do not have any other offsets for the 3. This was the sellers reply to my query about the offsets....
I am 100% this wheels will fit perfect on your 2012 335i and this is the only offset they have"
I suppose I will not be purchasing these wheels. It is unfortunate because I like the black LM style with polished lip. I think it would look nice on my Melbourne red.