Hello and welcome. There is a lot of reading you will have to within these threads. Ultimately, have the car inspected by a an indie, even if they charge you $150, it will save you thousands on buying a problem vehicle. Routine and non-routine maintenance on these vehicles are somewhat expensive at a dealer and less at an indie. If you are committed make sure you get the color combo you want, and not just what the inventory has. The X5's are just about always on the market. Autotrader, craigslist, bmw dealers. I did CPO and when the warranty expired 90 days later I had a CCV issue, although I am not sure if that would have been covered. Either way, these are fun rides! Good luck!