My M3 is 9 months new and has 4,620 miles on it. I just had the tires rotated in a diagonal pattern. I know it's sooner than the manual recommends, but I want them to last a long time. I've read in a couple of places that stock foam tires don't have the longevity as eventual replacement tires will have. I went to Autowerkes in Freeport, ME. You could eat off the floor in that place! They work with high-end foreign cars. That's where I got my car inspected, too. When they put it on the lift, I could see the underside for the first time! How completely different from an ICE undercarriage! For my peace of mind, I'll have the tires rotated every 5,000-6,000 miles.