How is a automobile windshield manufactured?
A windshield is assembled by two sheets of laminated glass with a vinyl sheet placed in between. The vinyl sheet is the strength of the windshield. This vinyl sheet also adds the coloring and solar protection to the glass. So if your windshield has a blue or green shade band at the top then it is in this vinyl piece. More than likely if your windshield was hit by a rock, the top layer of the glass was the only piece damaged. It would take a lot of force to break through the vinyl layer in between the glass.
