 BWM refuses to acknowledge that their rims are defective and crack as a result of normal driving, especially their 18 inch rims when coupled with run-flat tires.  We don't take speed bumps at 40 mph, run over curbs, or not slow for a potholes... events that might possibly crack a rim or break a tire.  Yet BMWs excuse for not replacing 2 cracked rims was that the cracks must have been caused by the driver, not faulty rims/run-flat tire combination.  In the past several years we have owned 3 BMWs... but this will be our last because of such a head-in-the-sand approach taken by BMW NA.