So why aren't all cars automatic?
Cars should be more efficient than a human at selecting the correct gear. The tech has been around for decades. These days it could scan the road and be better than just relying on current speed. Cars used to have a choke - now they don't, we got over that. We could even lose the accelerator as well as the gear pedal. Just have steering and brake, if you don't mind the car choosing your speed for you based on the conditions and the speedlimit.
I can't see true AVs ever working for the general case unless every car is an AV. Maybe for certain restrictied applications like a taxi on private land - or a Mars rover. There will always be people who want to drive themselves, which will confuse the AVs. But maybe self-drive won't be an option one day.
What I can see is more cars with driver assistance tech to make driving easier for the human (automatic parking, emergency breaking, lane following, heads-up displays - all available today). Some good tech may come out of AVs, but a car that can drive itself on roads anywhere on the planet? Probably not.
Where are all the autonomous trains? (OK, there's the docklands light railway) It's a much easier problem to solve. Get that done first, then fully autonomous planes, and then we can think about cars.