I was wondering what size rims I can fit on my car...98 M3 stock springs. Right now I'm running 18in BBS CH's...8 in the front and 8.5 in the rear (I believe...bought the car with em already on). How wide can I go in the front and the back without rubbing...also if I found a nice lightweight 19in how wide? Still trying to decide if I love the CH's or not...they're brand new.

Thanks,
Chris