Like you, I rotate my tires at every oil change and have been since new...But with stock suspension and now at 75K miles, I have noticed cupping on the inner rear tires early this summer. I've had it aligned, and still the same issue. Tire pressure is always good, I check it all the time. I guess it might be time to look harder at hard parts and consider the HFP suspension and a camber kit.I rotate tires at every oil change and have now seen that the HFP kit is indeed causing uneven wear on the inner edge of the rear tires. This never happened before with my car riding on the standard Si suspension. The wear pattern is noticeably different. I had 92,000 miles of tire wear experience with the original and now almost 25,000 miles on the HFP suspension. Rear camber will need to be adjusted if you want maximum tire life.