Muffler knocking noises

[Peter Ziobrzynski <pzi@pzi.net>]

There is a centrally located big muffler in Jetta that tends to rotate and knock
at the bottom of the car. I had this fixed at the last check on 24k miles. The
mechanic raised the car, loosened a bolt on the exhaust pipe on the engine side
and rotated or straightened the muffler so it was horizontal.
The knocking noises stopped for some 2k miles. Now they are back.
When at the dealer I noticed that most of the Jettas that I saw from underneath
had those mufflers skewed or rotated with the right side lower then the left.
This probably means that it is a common problem.

Now my bumper-to-bumper warranty is gone and I am curious if there is some
general wisdom on the subject in Jetta community. Any advise...
-- 
Peter Ziobrzynski,  <pzi@pzi.net>