Have an 2010 X5 35d with a tailgate that was making a knocking noise when going slow and making right or left turn. I wrapped the bottom of the u shaped latches on both sides of the small tailgate with approximately 1.5 inches of electrical tape and the center u shaped latch in the middle of the bottom small tailgate door. Noise is completely gone. Checkout davahad post in

http://www.xoutpost.com/bmw-sav-foru...r-hatch-4.html

Good luck. I actually sat in the tailgate area and had my wife drive around the neighborhood to isolate the noise.