Dude, unless they really fucked you over, it isn't worht gonig after soemthnig as nice and as expensive as a possession like a car. Post up a story about why you wanna do this, and what car it is and maybe we can help more. For s small prank, let the air out, unplug the coils, syphen the gas out, disconnect a sensor that makes them see a warning light when they drive so they'll be worried about it, but don't do any REAL damage.