Why can't they just shut it all down when they're done patching? Send out your final patch disabling networked functionality completely.
Nothing in the car should be reliant upon such services, hacking the remaining systems after this is disabled would involve physical access to the car, considering you can just as easily unscrew the pedal or cut the brake lines or what-have-you, that's probably an acceptable tradeoff.
Nothing in the car should be reliant upon such services, hacking the remaining systems after this is disabled would involve physical access to the car, considering you can just as easily unscrew the pedal or cut the brake lines or what-have-you, that's probably an acceptable tradeoff.