[Vwdiesel] '02 Jetta Honks When Backing Up

[Andrew .Libby]

My '02 Jetta has started occasionally letting out a fairly loud honk sound
when backing up.  It is not the horn.  It sounds more like a goose.  It
seems to be coming from the rear.  It only does it every once in a while.
I can't seem to figure out how to make it do it.  I imagine it has
something to do with the rear brakes, but am a little ashamed to say I
haven't even looked yet.  I figured I'd first ask if anyone has experienced
similar.