I doubt self driving cars will actually make it to prime time.

First our "state of the art" computer systems are anything but.
Most aren't even a computer any more. (they are only a half of a computer, like Winders is only half an operating system because in its base configuration it cannot tell you all the processes that are running, nor will it let you kill a virus)

Lets take the iPad as an example. Lots of people have bought an iPad, and think they own an iPad. But, they don't. Apple owns the iPad.

You can't even write an application and download it to your iPad without approval from Apple.

Apple has complete control of the iOS. They can shut down all iPads tomorrow, and they have done so, accidentally. (remember the iPhone brick?)

So you do not own nor control your iPad. Just like you won't own nor control your self-driving car. You are now playing russian-roulette every time you get into the car.

Second, the protocols for sending signals haven't even been thought of yet. Right now, what we have, is a system that is hackable at every level. If I want to take control of your iPad, I set up a wireless router where you will be, and once you access that router, I control all of your data flow. I can retype every web page you visit, on the fly. You can do the same thing with drones. You will be able to do the same thing with cars.

Third, the auto pilot is fine in areas which are well travelled and well maintained. However, most of the driving in america happens in rural areas around the farm. Places where there is little traffic, and very little use for a machine that would do 25% or less of the driving. Places where you are usually responding to some problem or another, like flooding, cows out of their pen (and on the road) or other hapinstance that changes the terrain.

Forth, the time of the automobile is coming to an end. The suburbs are basically an old folks home. The next generation is living in tight cities where they can walk or bike. Or they are moving out to farms. The era of cars meaning freedom has come to an end. Now, instead of driving over to your friend's house, you just snapchat them.

So, I do not see the self driving cars becoming more than taxis in certain cities. And thus, the large cost of implementation will never be paid.
After the first story of a auto-car that locks the passenger in the car because of a parking fine (or whatever) and people will start to avoid auto-cars.