I have used my wiper kit on my hardcoated windshield for a couple years now with now issues with scratches at all I know when I had wiped it before with a rag so I could see It would scratch easy I know I have had stone from a semi going by and if I had glass windshield it would of been toast just throwing it out I have been using with no issue's and man I love it I think a wiper kit on a windshield is a must