I have a 2011 6 cyl non-turbo which I purchased from a dealer with 4k miles on it (basically new). The car has had the steering rack replaced after year one (search for this, seems to impact models all the way through 2013, maybe beyond). I got the drivetrain malfunction message at 60k miles, but turned out to be plugs and coils going bad. Other than that it's been a very reliable car. Yes, glove box de-laminated, and my door seals (inside) are also discolored like someone pointed out above. It goes through brake pads quicker than my last X3 (not to mention tires every 25k miles). Most of that isn't really "reliability" though.
It has about 65k on it now, I plan on keeping it two or three more years which will put it around 85k miles (low miles because I have an e46 convertible that takes some daily duty). I've owned the last generation X3 prior to this, so logically I'd be looking at the next X3 at that time.
