Did you hock a loogie on his windshield??
No.. my mom taught me better. His.. Not so much.
I guess I would wait till I see him in line then take my claw hammer to his door.
Always carry a coke can (or bottle) with some old coke in it. Once the idiot has gone into the restaurant pour the coke onto the windshield wipers. It will dry on the rubber and the wipers will stick to the glass the next time they try to use them.
Or poo on it like that old hippy did on the police cart in New York.