even parking in well lit popular areas doesn't work.
even the car alarm doesn't work.
how many times have you been at the mall on a busy saturday afternoon and heard a car alarm go off? how many people even hesitated, let alone turn and look?
Now wonder, how many of those alarms are people stealing that car?
It doesn't take a lot to find a wiring diagram for an alarm system, especially factory ones...
I like the lojack system. It can be installed so you don't even know it is there. no lights, no alarm, no warning. If you don't know it is there, then you don't know to disarm it. Lojack is a great gps tracking system. It doesn't really help keep your car from getting stolen, not a lot can, but it does tell you where the car is so you can go get it back much quicker than trying to find it on your own.
another idea to consider. it wouldn't be that expensive, but it would take some know how to do the wiring. Computers have little USB locks. some of them don't even have to be plugged it, it just has to be within a certain proximity. I have no doubt that you could wire that into your car so that your ECU won't get power unless that usb is plugged in, or is within proximity.
as for the whole, what do you do to prevent your car from getting picked up by a tow truck.... nothing, if someone wants that car on a flatbed, they will just drag the locked tires, and that boot thing right up onto it. the only thing you can do at that point is to activate your lojack and go get it back.
I like lojack because of the system it uses, but if you are smart and would rather take care of it yourself, then you can install your own GPS set up and you can grab your gun and go get your car back your own way... either way works for me...

--additional--
your little things like battery kill switches and disconnecting your coil wire, or locking lug nuts... basically everything on that list will prevent your punk kid from stealing the car. but a "pro" is stealing the car to steal the car. he could car less about the head unit, or anything like that. locking lug nuts prevent your punk kid from getting them. I've seen it in south St. Pete a group of guys will roll up with 4 way tire irons, with a different key attatched to each end. they only make so many different ones. every new nissan all has the same lock, since 2005. every set of rims from rent and roll comes with the same set.
the point i'm making is that there are lots of little things you can do to prevent your average punk ass kid from taking your crap. But if you get someone that has put even a few hours worth of thought into it, there isn't a lot you can do to prevent him, or usually them, from taking your car. your best defense when it comes to that situation is to have the tools needed to get your car back as soon as possible. the less time you give them, the better your chances are that you'll find your car in one piece. From what I can tell, most of the thefts have been by the same group. so they figured out how nissan wires stuff and they are just going at it. probably ebaying parts, shipping engines over seas and scrapping chassis. the sick part about it is that they are probably only making a 2-3 grand off of a really nice car... and much less than that on some busted s13 that someone has poured their heart and sole into...