O.k. I've got these silly, 10K tread-life, summer only, super high performance Pirelli tires on my car, which are part of the factory Brembo brake/suspension/wheel & tire package. Unfortuantely, I had to have 3 patches for punctures in my front tires, one in one, and two in the other. Not the car or tires fault, just bad ju-ju. Despite having them balanced, and then re-balanced, I could not get rid of a steering wheel shake. Nothing is more annoying to me, so (fortunately) a fellow NoVa Mustang club member sold me two OEM tires he had taken off his (identical) car, and I had them installed on mine today. Presto, no more wheel shimmy. Why is that? Is there something peculiar about these 19", low-profile hyper-tires that cause patches to imbalance them, to the point of not being correctable? Is it not a balance issue, but rather an out-of-round issue? The money's already spent, and I'm happy as hell with the results, but I still would love to understand why they had to be replaced.