Threaten that friends from Canada will come down and drag him off to an arctic location. While suffering from -76 F temperatures, he will be forced to live in an igloo and eat raw seal blubber. Once a week he'll be raped by a polar bear and twice a month he'll take a bath the the ocean and dry off with sand paper!
j/k. I would try what RedLilPony mentioned. Maybe this little punks parents will be more affraid of litigation he is.
Either way I'll help you anyway I can from up here.
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White 1995 Mustang GT
Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer
My 1995 Mustang GT