Physical Access (Score 5, Interesting)

This issue surrounds physical access to the vehicle, at which point no amount of security is going to be able to protect it (it will only make it more difficult to do). Adding security would make it significantly more difficult for mechanics and enthusiasts to work with their vehicles. My vote is towards adding a notification light on the dash board for when a device is connected to the vehicle's computer (that cannot be turned off by the computer [e.g. controlled by an auxiliary system]), which would notify the user that something is not right (if they did not connect something).