I put after market wheels on every BMW I've owned, it's usually lighter than OEM, so better gas mileage and slightly better acceleration. I have the freedom to pick the color and style too, and I never had an issue with after market wheels. As long as you have the winter coat on them to prevent rust. Many people prefer to stay with OEM too, I always sold my OEM rims pretty easily for winter rims. If you get rims, I highly recommend getting 18" or larger, no 17" will look good, it's just too small for bimmers, if you don't want to waste the stock tires, then wait till they're worn out, then get 18 or 19s, you will regret getting 17", that I can promise you. Anyway, I just put these rims on mine yesterday:
