I am experiencing almost the exact issue described in this tread on my 2008 BMW 328xi (~42k miles): http://www.e90post.com/forums/showthread.php?t=175885 Click when changing directions and when going on/off the throttle - but in my case I'm hearing it from the front whereas most others report it coming from the rear. How people are describing this issue in that thread sound exactly like how I am experiencing it just from the back instead of the front. I replicated it for a couple different shops but they seemed hesitant to make any recommendations. What I am thinking is that I may be experiencing similar slop with the flanged coupler of my front diff. Any thoughts?