lotta things you might try, and a combination of them would prolly be best.
1) an alarm. sure, real car theives no how to disarm them, but if u r within earshot (like inside ur house) then it might help.
2) removeable steering wheel. make it tough to steer. If the theif knows you have this they may be able to bring their own and defeat it, but theyd prolly just rather steal your neighbors first.
3) wheel locks. self explanatory.
4) detachable face stereo and hidden or very well secured amps/speakers.
5) starter disconnect switch. If *well* hidden, this might help.
6) brake pedal lock. better than the club (how hard is it to cut through a steering wheel? not very!)
7) the family dog. Spot can smell a thief 100 yards away.
8) dont blare your stereo anywhere near YOUR neighborhood...
9) have a motion sensing light on your driveway, bright one, with the sensor area within range of your rig. No theif likes to work under a spot light.
10) low jack. good way to track down where ur rig has gone if it does manage to get stolen.
11) you could prolly rig up a anti-slim-jim gizmo in your doors. Couldn't be that hard, block off its ability to get down inside there and you could stop one of the easier ways theives get in.
12) put a cover over your rig at night. One with a cable lock on it. Heck, the comotion of getting it off or cutting it might be enough to set of the alarm, motion sensing lights, or your dog. Whats more, the theif has no idea if you have a stereo worth stealing or not... he/she might want a sure thing instead.
hmmm, thats all I can think of for now... any 1 else have any idears?
J