Thompson BMW

I had a relatively pleasant experience buying a BMW 3-series at Thompson. The salesman (Norm) was friendly, the test drive was very persuasive, and the price was pretty reasonable based on my research on Edmunds and other websites. However, I am a bit troubled by the fact that the BMW's runflat tires are having major problems with ride quality, cupping, noise and wear, necessitating replacement in less than 10k miles in many cases. Far be it for me to expect a salesperson to tell me these things, but the fact that this was never mentioned by Edmunds, Car and Driver, or any other automotive review site is pretty appalling.