A sexual act where one person wraps his/her head in saran wrap and watches as the asshole opens and closes from another person who is crapping on thier face.
Guy 1- "I heard Tommy really loved it when Janice gave him a DIRTY WINDSHIELD"
Guy 2- "I heard that also..."
Guy 1- "Could you give me a DIRTY WINDSHIELD?"
Guy 2- " Oh but of course!"