Hello All - Hopefully someone may have an idea on this, it has me
stumped!

I have a 1999 323i which has a quiet (but getting louder) vibration
noise coming from the right rear when the tach passes 2000 in 1st and
2nd.  It only does this in gear.  I only notice it when the passenger
windows are down, it's that quiet.

The sound is like someone running a stick over a washboard, like in a
hillbilly band.

Any ideas?