I expect eventually the software won't allow speeding when in autonomous modes. Why would it allow any illegal behavior? Stopping in the middle of the road at a green light? Turning right from the left hand lane? Driving without headlamps on 30 minutes after dusk, etc? These are all really rudimentary things to deal with in programming, simply disallow it. If you want to speed, you're on your own, minimal features like brake assist maybe still work. But making it possible for the car itself to break the law? I don't see it even in the medium term, and yes I'm aware the recent Tesla crash was speeding while Autopilot was on.