A properly installed kill switch would be effective but I might recomend gps tracking units. These days they can virtually do anything. There is a company out of atlanta that was making them for one of my former employers and this unit would call, text or email and notification you wanted wheither it being a door opening, alarm being set off or the car started. It would even sense the car being moved without the ignition going hot (tow trucks etc.). Honestly it would be a great investment if you want to keep your car safe. The best part about most of these tracking companies is there is no monthly or anual fee. You just pay for the uses you use.