I think even the manuals are fucked by computers to some degree these days. They don't last like they used to. See if we ever get anything that lasts past 300k after missing a gear and using the wrong fluid again.
But if you're really stuck with automatic, 90s models don't have too much electronics. Usually just a couple of solenoids. Nothing that would be easy to control remotely. They'd have to disable the entire car, and even then you'd have manual steering and brakes in your control to make it to the side of the road.
Yeah, cars being hackable was common knowledge for a long time. I think that's why they introduced the electronic assisted steering. By the way, that's a fucking terrifying thing to have fail. Imagine the exertion of manual steering from a stop at 60 mph. As for Jim Stone, he's not always right.