This is what I've said before. Even a remote possibility of a glitch or hack with SDC's would be unacceptable. The safety measures of their network would have to be on the level of the airline travel industry and resilience to errors or hacks on bank grade encryption. Just imagine if a hacker got into the system and commanded every car on that network to suddenly turn 90 degrees. The freeway would be bathed in blood.
How it is that Uber and Tesla thought there would be level 5 autonomous vehicles in the near future is beyond me. The matter of the car driving itself is already a giant hurdle but only a small piece of the puzzle, even when they can get it perfected which in and of itself is going to be quite a while. Legalities, network security, insurance issues and the infrastructure likely needed to allow the car to operate in adverse conditions are huge issues they'll also need to address.