Just be warned that any loud noise, be it a un muffled boat, a lawn mower at 7am/9:50pm, a loud stereo, or anything that could be considered "Disturbing the peace" is in fact, a crime. Regardless of the time of day, (I always thought there were certain hours when noise was OK, I was wrong), and could get you a summons to appear in court to answer the charges. I see several ideas about his vehicle. Some of which could result in a lawsuit you could lose. Best idea, and it is done from the outside of the car, is Limberger cheese in the air vents/cowling vent. Shread it up into very small pieces and dump it down the vents. Hot sun will do the rest. Be sure to clean up any residue on the outside.......AND, spill some sugar in the street or driveway next to his gas tank. DO NOT sugar the tank, just make him think someone did. He'll probably have the car towed and drained, at his expense, only to find nothing......Another "pain in the ass" trick is plastic coated playing cards in the gas tank, (a little tougher with the un leaded flapper deal), 6 or 8 cards will just float around in there until the pump starts sucking. Then the cards gather around the suction, block the fuel flow, engine dies. Without the suction the cards re float, car starts, goes a few miles and it all happens again.........Do not do anything that damages property, or creates an un safe condition that could result in injury. Harmless pranks are one thing, just don't get caught. I personally like the Limberger cheese in the vents, about the only way to get rid of the stench is to burn the car.........You can also spell out "DICK" with super grow grass additive. The "dick" part will out grow the rest of the lawn without doing any real harm.......MP