I wish this thread would have take off! I lo e funny stickers.
Mostly, my cousins and I swap out valve stem covers at family gatherings! (Middle finger, genitalia, ball sack...) but there was a magnetic bumpersticker that floated around for a while "I'm so gag, I can't even drive straight". He works high-rise cranes as the crew chief... his guys would hardly talk to him for a week! It was great!