The worst car dealer ever dealt with: bought four run-flat tires for my X3 with the price of $400 each from the dealer. Within 2 month period, one tire had a crack. Went back to the dealer, asking for replacement since I thought the tire was still under warranty. It turns out that I have to pay for the replacement tire. The dealer said the tire's crack was caused by some kind of impact. What I do not understand is how they determine the crack caused by impact and if they had any data to show how much impact would cause such a crack. Would never buy any cars and any parts from this dealer again. Very poor attitude toward customers who had loyalty with them before. BYE, Chanpman BMW!!!