just make a transceiver. Just make sure you are not transmitting on a frequency prohibited by your country's government.
all you have to do is make sure the "alarm deactivation" button is on your transceiver. When you press the button, it sends the signal to the transceiver to turn it's alarm off.
If it is on, and someone opens the door, then the transceiver in the car sends out a tone to yours and then you can go chase the intruder.
Here's the interesting part. They have no clue what is going on, and if all the lights are off in your home, they probably think they get an easy ride.
By the time they figure out how to turn the ignition on, you would have already captured him. :wink: