Well last year my haunt partner used that window paint on his car to advertise the haunt. I don't know how effective it was tho. Not all of it came his window too lol. I think the sun baked it on, you can still see it a little after washing it. You can try it out. I have seen a local haunted house here use magnet's to advertise their haunt as well. You can maybe give that a try.