No problem. It may take some time (and phone calls) to dealerships as well as replica companies on what will and will not fit. Also, check eBay for X3 wheels. I've seen replica X5 wheels which are said to "fit" the X3. Again, contact the seller(s) about this to confirm. For example: http://stores.ebay.com/EurotechBMW

I just went through all of this trying to find new wheels for my X3 (didn't get X5 wheels, though).

Good luck.