A good option is to install one or two hidden switches that need activating corectly for the fuel pump to run - even with your key they won't be able to take your car.
I think it's Autralia where like 80% of the car theft are done with the owner's key? (Too lazy to look for the citation)
This is largely true. I own an Elantra, had a window, the ignition, and steering column trashed, and the would be thief failed to actually steal the car. I was still out almost $1200 after towing and my deductible.
Having a steering wheel lock has worked so far since then, but there is a tremendous incentive for someone to ruin my car again given the chance, since it'll (maybe always) appear to be an easy target, kill switch or no.