In college, I worked at Circuit City doing car audio install. One of the guys I worked with was a real douche, the type of person who "forgot" to bring lunch money and borrow cash from others he would rarely pay back. He would get into other people's tools without asking if they left their box open, sometimes tools didn't make there way back. I could go on, but I think you got the point.
Anyhow, if he ever needed a ride from work to his dorm I would roll my windows down and lock the, so he couldn't put them back up. Then I would blare Wesley Willis or Elvis singing gospel. People on campus or in cars in traffic would laugh, give us really odd looks, or both. He would get real embarrassed. After I did this a couple of times he stopped needing rides from me.