I was at my cottage about a month ago and when I parked my car and started to walk away, I looked back (as I always do
) and I found that there was something hanging from under the car near the muffler.
After much worrying and, at one point, thinking it was a bomb or something, I found out that it was a vibration absorber (P/N 18201433175, #18 on diagram) attached to the exhaust to prevent a rattle at idle:
I found that the heavy damper is merely bonded
to the bracket from the vactory, doomed to fail eventually. BMW even attached a little braided metal safety tether in the event it falls off the bracket to prevent it from killing/mutilating/destroying whatever is behind you. Unfortunately, this part is ~$120 or more depending on where you look, so I decided to fix it myself. It's really simple!
Below is a stock part:
The allen bolt is there to clamp down on the safety tether only. My solution was to remove the tether completely and replace it with a large washer which will allow the bolt to clamp the weight and the bracket together. Here is the end result all painted up:
Red arrow is the washer, green arrow is the allen bolt.
Here are a few more angles:
On a side note, the bolts that held the bracket to the exhaust were rusted to the bracket, so when I removed it from the car, both bolt heads were snapped and I had to drill them out and re-tap the bracket.