I would think it would take a really 'harsh' towel to scratch auto glass - but I'm no expert. I hope ChuckMotor's are different from mine. I've seen no scratching and the
Glass Cleaning cloth has been completely lint free. I like it because it leaves no streakes. I'll keep an eye out for scratches but my windsheild has 'hit ' the sun many times while driving and they still look crystal clear to me.