Alternatively, you could purchase a tiger cub on the black market, train and raise it, then allow it to live inside your Zed. I'm sure that would deter thieves.
On a more serious note, I used to have a neighbour in Cheltenham who owned an RX-7. The alarm system he had was pretty trick because I simply wanted to take a closer look inside it, put my head near the window to look inside, and the bloody thing made quite a loud beeping noise basically to warn me away from the car. That could always work just to notify you if someone/something is near to your car!... that is, if you are in ear-shot of it.