No idea how the law works in Oz, but here you can't try to kill a guy because he stole your car, especially if he's running away from you. We can talk tough but the law is what it is, the driver could very well be charged. I'm solidly 2A, RKBA, will defend myself and family with deadly force, but none of my cars are worth someone's life.
I wouldn't run him over for stealing my Titan, I would just call the cops and let them do their job and claim it on insurance. If he stole my Patrol (which I don't have) but if I did own one I would absolutely chase him down and run him over, just because it is nearly impossible to get one of those gems in the States.
Don't steal ****, criminals get what comes to them, and they ought to embrace it. Now, the tax payers have to pay for this scum to sit there, and then have to pay to take the property owner to court. Should have finished the job, and the legal system needs to be a bit more harsh on property theft.
Not all people have full coverage insurance. Especially on older vehicles or trailers.
It seems these days that the bad guys do whatever they want and hope for leniency in criminal court and sympathy in civil court. If a bad guy gets hurt or killed as a result of the actions the he chooses to take, then so be it.