Here is another theory to make things complicated.
I think it's the metal and/or plastic clips that hold the rear driver side window molding on. Or perhaps it's the plastic alighment tabs that were left in the window from the assembly process. If you push on the outside of the molding near the the front of the rear window, it makes the same clicking noise as when you hit a bump or expansion joint in the road.
I know it sounds stupid, but I removed every piece of plastic, foam, and the seat belt on the driver side and I still had the bump activated clicking noise. Arrrghhhh! Never did positively solve the problem before I sold the car. The guy that officially solves this should get a prize from the club
Mike
[This message has been edited by FargoRS (edited February 19, 2001).]