Not sure if I replied to this before, but on my 98 I had some
small plastic shim son the outer edges of the dash where it meets
the windshield. See this image:

http://www.valisys.com/people/krn/dash.jpg

The image is the passenger side looking at the point where the
A piller trim meets the dash. That is the speaker grill in the
foreground.

In the image, you see a rough torn edge where it is circled
near the bottom (the top part is the edge reflected in the glass).
That edge is the plastic shim after I mangled it. It was originally
straight and just touched the glass. It would squeek when cold.
You can place a business card between the plastic shim and the dash
and tape the card to the windshield glass to see if that is the
problem (if so, it goes away when you do that).

You can actually see the plastic shim, but it can be tricky to see it.