In Germany you are always liable for all damage your car does, no matter whether it is caused by your own mistakes or because of a technical failure. This might not seem fair but the second piece to this puzzle is that you are also forced to have insurance.
Making it clear and unmistakable who is liable makes sure that it is always clear who has to pay for the damage done by cars. The insurance makes sure that whoever is liable can also actually pay. That way the victims don’t get left with the costs (no matter how much money the liable person has) and for the liable person accidents don’t turn into life-destroying events.
This is a working system and I see no reason why it wouldn’t work with driverless cars.
(Even if you want to change it and switch liability from the owner to the manufacturer, that’s not really an insurmountable problem. The solution is – as always – called insurance. Google would just have to insure every car they sell. That’s no big deal, seeing as cars are already pretty much all insured. The cars would get more expensive but the cost of ownership would decrease since it wouldn’t be necessary any longer to pay for insurance. Such a change would be pretty pointless, though. It would only serve to switch around who pays. In the end, though, the owner still has to bear the costs.)