So you know your windshield isn't tempered glass it's laminated glass. Tempered glass, like on your side windows, is designed to shatter into tiny pieces if hit. Your front and back glass is designed for much higher impact than the sides and will chip or crack. Don't confuse hardness and toughness. You won't see the micro-scratches that steel wool will leave but they're there. Glass experts (engineers not auto detailers) do not recommend using steel wool on windshields. There are lots of non-abrasive windshield cleaners on the market.
USN - RETIRED NUKE