Dogshit in the exhaust pipe is a good one as well. Did that to a cunt of a teacher when I was at school. Put stones in his hubcaps as well. Stupid bastard couldn't figure out why the fuck his car made noises when he drove it. Finally took it to the garage and after Christ knows how long they had it but eventually found the problem. Some bastard grassed me up and I ended getting caned. Happy days