That's a difficult line to draw, especially when (as you describe with the GTR) the job of the computer is to react faster than the human. For 95% of my car trips, I would feel plenty "in control" if I could tell my car where I wanted to end up and let it take me there however it thought was best, assuming it got me there reasonably quickly and safely. After all, if my car was driven by a human chauffeur, nobody would question whether I was in control. Why would an equally reliable computerized control system present a greater challenge to my feeling of control than a human chauffeur?