Honestly I don't care how remote it is. Maybe someplace in the southwest where they have effectively unlimited visibility, but as I grumbled about after the journalist PR stunt, they don't really know the possible outcomes of their tinkering.
Even in a non-hacking scenario there are plenty of weird edge cases that can arise in car computer systems. Catch any of John Hughes' talks about QuickCheck and he'll describe finding perverse bugs that would take a combination of specific inputs and could result in very negative outcomes for the driver.