Death knell
The motor industry employs more people either directly or indirectly (filling stations, Halfords, car cleaning, repairs etc). Cars are quite personal things, they provide the freedom to go anywhere at any time without having to pre-book or buy a ticket. If I want to go to London, right now, I could it's 200 miles away but my car is sat outside. When I'm in my car no-one really knows where I am. Cars are great, it's why we're so picky on which one(s) we have.
Now an automatic car, that you just sit in whilst it obediently takes you from A - B would be more of a personal taxi, the performance, handing etc would be redundant, buying a more powerful car would be completely pointless as the car would only ever drive safely and at the limit. The model for a luxury car would be very different, now they'd be a small mobile office, somewhere to write emails, watch a film, update your status, do some eShopping, be sold something, chat to other 'drivers', have a drink or a snooze. But as most car journeys are fairly mundane and you're just along for the ride then the car is then just a personal taxi, when was the last time you cared what sort of car the taxi driver turned up in?
therefore renting a driverless car as and when would start to make sense, you'd pay a subscription and have some kind of 'app' that you could push when you wanted picking up and the taxi would take you, your passengers and shopping to where you needed to go.
It would eliminate traffic jams, streets jammed up with parked cars also. There would be no need for all the street furniture such as traffic lights and matrix signs as the automated vehicles won't need them.
It all sounds bliss, however the automotive industry would be on its arse as people wouldn't be buying cars, nor would they be attached to them as before, they'd simply be an appliance. All the secondary employment it creates would also be in trouble, you'd not need to go to a service station, you'd not need to sit in that cafe eating a £10 bacon sandwich, you wouldn't ask the taxi to go through a car wash or spend the night in a travel lodge to break up the trip, you could sleep in the car.
The list of jobs and industry that would be at risk is difficult to calculate but it would be huge.
You'd also lose that freedom and individuality, the taxis would obviously know exactly where you are, where you went, would log and profile your trips to determine what it could sell you.
I still think it's unlikely to happen soon, if all cars are driven by Google and there's a glitch that causes an accident and someone dies then the driver at fault in the crash would be Google, everyone that bought or signed up to their scheme would now have a car that could kill them and would be reliant on a software update to make them safe. The lawsuits would be incredible and wipe Google off the planet.