I found a desi security system for 800 PKR only and if you're connected to the guy then 450 PKR only, which is as per my thoughts better and more efficient then these tracking devices.
How it actually works:
They install something, and hide a button in your car. So as whenever you open you door, the device activates a timer of 1.5 minutes, after the timers runs out. The car shuts down itself unless you push the button to reset it.
Whenever you open you door it activates and shuts down your car after 1.5 mins. When you get back, push the button and your car is all set to go.
Ill start a topic this saturday as I will go to install it in my car.