This looks like it would give you similar functionality: ProTrak Live Dial-Up Real Time GPS Vehicle Tracking System Product Comparison
All i am saying is that anything that puts out a signal is releasing energy/light/radiation/@ a certain wavelength/whatever. You can buy gear that simply looks for this released enegry and the closer the reader gets to it the more it would beep for example. The physics i am thinking of is very simple. I am not saying "read" the signal but simply pinpoint an area that has the greatest signal strength. "LoJack transmits on a radio frequency of 173.075 MHz. Vehicles with the system installed send a 200 ms chirp every ten seconds on this frequency. When being tracked after reported stolen, the devices send out a 200 ms signal once a second.[4][5] The radio frequency transmitted by LoJack is near the VHF spectrum band used by television channel 7 in North America,[6] although there is minimal interference due to the low power of radiation, brief chirp duration, and long interval between chirps" So all you need is a device that can pinpoint a signal... not rocket science...
I bought my Prius last year because my previous car was stolen. My old car had Lojack. I got home at 7PM and went back out to my car at 5AM the next morning...only thing is my car wasn't there. Called the police to activate my Lojack. They told me a professional car theft ring can strip a car in under half an hour. So, in reality you have a very small window in which to recover your car after it is stolen. Lojack now sells their "early warning" package - if your car moves without the Lojack key fob in the vehicle it sends a signal to Lojack who then calls/emails you. Problem is it can take up to a half hour before they notify you...and your car is stripped. I didn't bother getting Lojack on my Prius because you can't move it without the SKS or a flatbed (as pointed out earlier). I'd say save your money.
I'm not a fan of Lojack simply because I don't like the government intrusion into my life. It's a little too big brother for me.
