Well, I bought the BMW yesterday. And it's a beautiful car, if I do say so myself. But I nearly walked away. With nearly 70k miles on the clock I was told by the used car salesman (Chevrolet dealership) the car came with three months of warranty (specifically covering powertrain). I asked to take the car to a BMW dealership for them to inspect the car. To their credit the Chevy used car salesman agreed. I paid $135 (worth it) to have the BMW techs inspect the car. The sheet of items came back totaling about $2200 worth of parts and labor. The Chevy guy nearly lost his lunch when he saw the estimate. He offered to repair/replace the items at the Chevrolet dealership service dept. I said no. I wanted the price reduced by the $2200 or no deal. The plan would be to have the items repaired by a certified BMW mechanic. The $2200 reduction off the sale price didn't fly either. So we split the difference. Since then I discovered the car is still under the CPO warranty until December 2016 and most of the repair items are covered. So it worked out well. And I own a wonderful car.
