I just rotated my M3 RWD tires at ~6,000 miles. On my last car (front wheel drive) I didn't rotate the tires and the fronts would hit the limit and need replacing. If I only replaced the front tires, the shop insisted on putting the new tires on the rear and then the rear tires got rotated to the front. Then those wouldn't last long and I'd be replacing them and again the new tires went on the rear. So with the M3 I'm hoping I can stretch them out evenly and do all four tires at the same time. Especially if I want to change make/model I don't like having non-matching tires on the front/back.