One problem related to ball joint has been reported for the 2012 BMW X6. The most recently reported issues are listed below.
Driveshaft universal ball joint malfunction. Shows it's on recall . Engine turbo/supercharger failure. Engine coolant malfunction. The car stalls from the turbos malfunctioning & I feel the left wheel is about to fall off from driveshaft which makes a loud noise when you accelerate.