I have an autowatch hooked up fine along side my hks TT
basically you can leave the car running close the doors, lock the car and arm the alarm.
once the engine shuts off normally the alarm automatically does the rest of the immobilisitation etc...
if someone breaks in while the car is still running on the tt, as soon as the handbrake drops the engine dies, and alarm goes off.
Seems to be a fairly flawless system..