If you can come up with something that's actually effective, then maybe you could work on one for car shows. There's always the proverbial guy whose car is so earth-shatteringly fabulous that he must use two parking spaces right in front of the DJ trailer!
Even better, we had a big show last Tuesday night -- but not without its share of idiots. I was one of the first to arrive, and I parked my Thunderbird right across from the trailer, in front of a restaurant (Main Street Trattoria, with several tables outside on the large sidewalk). At least four others also parked there, beside my car, and indeed many of the diners came over to gaze at the cars and comment on them. The entire street soon became PACKED with cars, to the point where many could not even get in. Well, three of those cars did not sign in (there's a $10 registration fee) and just as the crowd was gathering to accept door prizes and trophies, these three dimwits decided to leave -- and we all had to make way to let them out.
But it gets better. The fourth was a Corvette with a racing motor, parked right in front of the restaurant's open front door. When the show was over he started the motor, making a tremendous noise that was WAY beyond legal, and let the thing idle while he put away his signs, his folding chairs, his flags, and all the other crap he had surrounding his precious car. He kept the stupid thing idling for at LEAST 45 minutes! Diners were getting mad at the noise and the exhaust -- which blew right into the restaurant itself -- and several went over to the owner, telling him to PLEASE shut it off. When he FINALLY got in the car to leave, he raced his motor several times, deafening everyone and blowing even more smoke into the restaurant (who sponsors the show!). This guy was so delusional that he thought he was really impressing everyone with his souped-up motor! I think he needs an attitude adjustment.
BTW, I not only signed in, I'm a show sponsor.