 I owned a 328is which was a truly great car.This led me to believe that buying a used 2006 X5 4.4i with very low mileage was a safe bet.Wrong.We have owned it for 18 months - and had non-stop troubles - expense - and time wasted at the shop.The latest - It has taken BMW 8 months and 5 trips to the dealer to determine what is causing the coolant leak we have.We still aren't 100% sure - but now they think the heads will need to be replaced - or perhaps the entire engine.$25K wasted on this vehicle. I'll never buy BMW again.The ultimate driving machine - for driving to the shop.