Having my 04 z4 repaired while on the ramps the garage guys found that a number of bolts holding the driveshafts joints had come un done one was about to fall out completly!!!!!! get under your cars and check espicaly older ones
the bolts are the conection from the hardyspicer joint which conects to the hub if they are loose you will easly see them worth puting a spanner on all of them see if they are tight