Right now we can't show you ads in your car, of course, because you're in command of two tons of steel moving at high speed, so your attention needs to be fully concentrated on that task. But if the car could drive itself, think of all the ways we could monetize that newly tappable reservoir of attention! It'd be a gold rush!

He doesn't say that, of course, because the vision of a world where you can spend your commute playing with your kid is a much easier sell than the vision of a world where your car becomes a kind of rolling Skinner box, with you a literally captive audience (what are you going to do, step out of a moving vehicle?) to be bombarded with messages by the highest bidder. But... yeah.