He doesn't tell us how the AI would escape, so there's little to discuss there. But I definitely know how to prevent the AI from escaping: pull the plug. I wish Eliezer and others would set aside meta-AI (dire predictions and worries about AI, the coming singularity, etc.) and concentrate on the problem of creating AI Guess there's no money in that. If only someone would pull the plug on this nonsense...
I would consider that sentence as a candidate for "understatement of the year".
(Don't get too caught up in the "cars" part. What the superhuman AI intends to do hardly matters in the end; the absurdity is part of my point and deliberate. Only a vanishing fraction of possible primary motivations end up with happy humans on the other end.)