I am experiencing a similar clacking noise on my x6 coming from both front doors when I make sharp turns at low speed and/or hit small path holes.
At the beginning I thought it was from the internal plastic panels, but it turned out that if I slightly open the front windows (1-2mm) the noise almost disappear, anyone experienced a similar issue?
What's causing this?..it's really annoying and almost embarrassing if you have a passenger win the car.