I keep my Crossies in my locked garage for the summer when I drive them regularly, and in a locked storage unit for the winter when they hibernate. I guess leaving the keys in them in the garage is risky, but I pull the batteries for the winter so no can start. When I park them outside, I generally try to park as far from the riffraff as I can, mostly to avoid door dings, but also to discourage lurking around the vehicle.

I suspect cars are stolen for joyriding purposes or because they are to be parted out. Garaging reduces the occurence of the former and there is not a huge demand for parts to make it worth a chop shop's trouble.

And as pointed out, the keyfob interlock makes it damn tough to start without the proper key.