70k. The car will make a whine(resonating whine) that sounds like it is coming from rt rear. Sounds like the caliper is dragging a bit. It only happens when you go a few miles, then starts. Sometimes it does'nt. If you apply the slightest pressure to the breaks it immediately stops. If you turn left(i believe) it stops. It is NOT a bearing noise(obviously) and the wheel does not get hot. Could it be a tire. Has Michelin MXV4'$ which I personally do not like on either Benz(noisy). It comes and goes and is never heard under say 40mph. It is the darndest thing. Of course it never happens when mechanic drives it because you normally have to go 5 or so miles before it starts.