Windshield Glass Cleaning
WARNING: This page is about a different car, the 2002 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Clean the windshield with windshield cleaner, GM P/N 1050011 or equivalent. The cleaner should not harm the paint finish or scratch the glass. The glass is clean when the water no longer beads, but sheets across the entire glass surface.