Get an adult friend with a macho, low voice and a good knack for acting to call and pretend to be a detective with the criminal investigation division of the nearest police department. Make sure he calls the most gullible of your potential wheel-lifting friends--the one who'll squeal like a girl and spread the word the fastest.

Then have Officer Macho just mention that the DARE officers at school (or whoever) got word that there's a plan afoot to jack some hubcaps. There's been a rash of crimes like that in town, the officer can explain, and they've been perpetrated by a pair matching this description. (Here he gives a flawless description of two of your pals, enough to scare the liver out of your guillble friend at the other end of the phone.) The officer can throw in some other scary tidbits regarding drug posession or any details you know that can be used against them. The officer is calling because he needs schedule time to question Gullible and the potential wheel-jackers about what they know about this and other crimes.

Then you jump out, ideally with the cameras from "Punk'd," and just enjoy the fun.