Here some options I would recommend:
1: Find an old grandpa with a HAM radio setup and old high power HF amplifier. Pull a wire across your yard (dipole) and hook it up to the antenna tuner and the amp. Then let the old man ragchew with his buddies on the air while he is overdriving the hell out the amp. This will produce very high rf and interference, will get picked up in this stereo speaker wires and will make the loudest noize possible. The best part this is LEGAL and it will jam his radio alltogether making it unusable even listening to a CD... :) If someone shows up complaining about the interference, you say that we got the amateur radio licence (that's why you need the grandpa) and thell them to get the hell out!!! Then there is nothing that FCC can do either...2: Wait till he turns the volume the loudest and take your transmitter and feed it with very high level of 30-60 Hz sine wave. This will blow his speakers out, leaving him with no stereo to listen to... : ) : ) : )
PS: Don't take the blames of these f***in "legal" people to personal. Just think that they have no life...
Have Fun!!! AntronX