[ugh]

I have no clue about the legal situation in the US. I do know that in my native Germany, the driver is always liable (even if not guilty).

Since anyone who owns a car (and wants to drive with the same on a public road) has to have insurance this really is no big deal. Currently accidents can result in you having to pay more for your insurance and different people have to pay different amounts of money (an 18-year-old with a Golf GTI has to pay more) but there really is no rational reason for insurances to do that when someone is driven by a robot car. Insurances are interested in statistics, not fear mongering.

I really don't see the big problem. Compulsory insurances solved the problem of liability without guilt a long time ago (1940 in Germany – hey, it's a Nazi law).

You might argue that the manufacturer of the robot car should pay for the insurance but I don't think such a change would even be necessary. Even if, it wouldn't be a big deal.