After I got all the trim off, I checked out the gasket, and it appears that no sealant was used. The gasket moved pretty freely on the car body, and you could easily separate the gasket from the glass. You could also see the little openings in the body caused by the "tabs" that seat the windshield gasket along the cowl (see photo). It appears that water was getting in through the openings for the tabs, among other areas. I sealed around the gasket, and sealed the gasket to the glass. We're supposed to have rain today, so we'll see how it holds up. Thanks for all the help.:-D