nasty squeaky noise

[Lee M. Levitt]

Here's a sticky one...my S6 avant is making a nasty plastic on plastic (or
plastic on metal) squeaky noise from the rear hatch area. I *think* it's
coming from the right rear C pillar cover, and I removed/replaced it. Didn't
seem to have any effect, and I *think* the mounting posts are all aligning
properly. There isn't an obvious one that is not aligning...but it sure does
sound like one of those buggers is scratching against the metal underneath.
There's no obvious wear spot, though...

What else could be making this noise from the rear of a '95 S6/A6 wagon?

Help!

Lee
'95.5 S6 avant
'96 A6 quattro avant