Re: If a plane can do this, what happens to cars?
It already did.
A few years ago, Toyota made the news after several of their vehicles crashed at high speed. In one horrifying case, a passenger called 911 for advice as the car accelerated out of control.
The proximal cause was stuck throttles.
This failure mode is easily managed by shifting into neutral to disengage the engine. Some drivers did this, some did not. Some of my friends were terrified this might happen to them. They simply had never been told how to deal with such a situation and did not have the systems knowledge to figure it out themselves.
Operators must be trained and skilled to manage the systems they are responsible for.