The former head of Google's self-driving car project has said that self-driving cars are decades into the future.* Even if that's too pessimistic, nobody today knows what a self-driving car will look like, what kind of algorithms it will run, and what kind of sensors it will need to get there. I'm afraid this pronouncement is another sign that Mr. Musk is taking his investors for a ride.
"How quickly can we get this into people's hands? If you read the papers, you see maybe it's three years, maybe it's thirty years. And I am here to tell you that honestly, it's a bit of both."
This statement is based on what he is aware of at the time. The most pessimistic side of it is purely a data game, and Tesla's ability to have 100k cars collecting data for them will give them a significant advantage to accelerate their progress.
* http://spectrum.ieee.org/cars-that-think/transportation/self...