Funnily enough, my need for controls in self-driving cars isn't the one you usually hear ("I need to be able to take control in an emergency") - as has already been amply researched, (1) the cars are likely to be much better at not getting into trouble in the first place than their cargo, and (2) suddenly handing over control to a human who's been dozing away watching the scenery, reading a book or whatever, simply is a really BAD idea - by the time they've worked out what's going on, it will be too late anyway, and anything they do is likely to make things radically worse, not better.
No, it's a far more pragmatic, human one: Not every car journey I make is a predictable trip from point A to point B, with no regard to what comes between. Sometimes I don't know what route I'll take, until I take it. Sometimes A and B are the same place. Sometimes I don't even know, when I set off, where B is. Sometimes my plans change in mid-journey, at very short notice. And sometimes, how ever good the traffic updates are, I'm likely to spot reasons why the car's preferred route isn't the one to take just then. So I need a reliable, simple interface that will give me enough control over my "autonomous" car to get it to take a particular route, pull over, slow down, speed up and whatever. Because, say, I want to pop into that little shop we just passed, that I've never seen before. Or I need a comfort break. Or the dog's been sick. Or I simply decide I want time to take in admire the stunning view on that windy little back road. What I don't want, and would think very carefully before buying, is a vehicle that takes away some of the freedoms that come with driving for myself.
I have little doubt that, if the time ever comes when these machines finally overcome the hurdles (not least, understandable human prejudices) and make it onto the market (and, frankly, I hope that's not so far away - it looks to this casual observer as though the technology is reaching a level of maturity wher ethe hurdles are legal rather than technical), such features will be there - because, frankly, they're obvious, and any offering that doesn't have them will lose out to the ones that do. But they're definitely needed. Google's prototype's lack of controls is a publicity grabber, pure and simple.