Firstly, I hope you get it back...
If only Australian law would allow us to install alarms that electrocute the thief...
In Europe, Citroen have an alarm that delivers an electric shock through the steering wheel when a thief tries to drive the car... Or even better, one alarm from South Africa electrocutes the thief through the seat.... This one delivers a slightly stronger pulse that knocks the driver out cold...
I can't imagine why it is not allowed under the ADR's but it would be effective....