I have an annoying rattle coming from the left rear of the car. it is a bone stock 02 cls.

I had it in for service 2x both times they say it is completly normal.

I took it to the autobody shop that has done work on the car, they say it is the tail pipes. they are meant to hang loose and that is where the noise is coming from. It only happens on the left side and it occurs when I go over bumps or make tight left turns, such as 3pt turns or complete radius uturns.
is this normal?