I have a 2002 m5 with 158000 miles. On a recent trip I was 1000 miles in and developed a vibration under throttle and off throttle. It seem like performance has been lost. Also there is a loud clicking noise from a dead stop and a horriable vibration and it continues through all gears. The gubio and the center driveshaft bearing are in good shape. The clicking noise sounds like a baseball card on a bike. I lifted the rear end off the ground and turned the rear wheels and the clicking continued. I did notice that the front bushing on the differentail seems to be bad. I am kinda worried that it may be the diff. How often do the rear diffs or cv axles go out. Can anyone help me here?