A huge problem with these complex technologically advanced cars is that they are basically rolling computers now, with WiFi. With that comes the possibility of hacking.
And yes, hackers can actually control your car. More and more cars are using "accident avoidance", which means your brake pedal is no longer a mechanical device, it's fly by wire, controlled by the onboard computer. Same goes for your steering if you have "park assist", where your car can back into a parallel parking spot.
Here's what freaked out the automakers:
https://www.youtube.com/watch?v=oqe6S6m73Zw
Ford and Toyota have spent millions trying to close potential holes in their software. All this after a couple of hackers showed the world how they could control your car from their laptop PC.
This will only get worse and worse, as now they're talking about devices that the police could use to disable your car, forcing it to apply its brakes. They say it's to prevent "slow speed chases", but as with anything, this device will fall into the hands of bad people. I'd hate to think of some young female driver on a rural road somewhere having some creep driving up behind them, and using this device to stop her car.
Technology will be the end of us all.