A vehicle tracker will also help to recover your vehicle if the remote key fob signal is jammed and you don't notice when leaving the vehicle, This jamming device costs less than £50 and is getting more popular as they don't even have to break a window to gain entry. If you see some one emptying a car or taking a laptop out a vehicle and no alarm was sounding you would think they owned the car or van.
In some cases they jam the remote key fob signal and when the owner is out of sight they will enter the car and plug a diagnostic machine into the OBD port and program a new key meaning they can simply drive your car away.