I got your PM but couldn't reply ( you are currently not accepting PMs). Anyway, You can fit up to a 8.5 in the front with a 35-45 mm offset with no more than a 225/40/19 tire(225/30/20 for 20s). The rear is what you have to be worried about. You can fit up to a 9.5" but the key is to get it with a 40-45mm offset (i think M3 replicas are like 32+ mm offset). The key is get a higher offset so the wheel will tuck into the fender and will not stick out. You could always go for a 7.5" rim in the back. In any case however, I think you will have to do a little modification to your car.