Noise from the area you refer to could be 1) The center support bearing rubber isolation has degraded and the driveshaft should be inspected for same and repaired/replaced straightaway. 2) A subframe/differential rubber isolation mount failure. 3) Bad rear shock mounts. I strongly recommend you seek out someone to put the car up in the air on a lift and inspect it for the unsafe issues that I have just presented, you might want to tow it to your BMW service provider to accomplish the inspection, be safe, do not take chances.
January, 28, 2011 AT 5:38 PM
Thank you for the info. I think it sounds more like a sharp electrical popping than frame /differential/shocks. But I will see my repair guy ASAP.
Again thank you.
January, 28, 2011 AT 5:43 PM
My response may be a little over the top, but you can agree I'm sure, that noise can be different things to different people. Cyberspace has it's limitations.