"So no. No company would take that risk. And anyone stupid enough to try would not write perfect code and would be sued out of existence after their first patch."
There are two options. Do it here (where here is wherever you live...) by convincing YOUR government to set up the appropriate legal standards. Or let it get done elsewhere (hmm, Singapore, China, Taiwan, Korea) where the government will simply make a decision and mandate that as long as the cars have insurance there WILL BE NO LAWSUITS...
With option A, your town, city, state/province may reap some of the early benefits (aka jobs, profitable local businesses, safer roads sooner). With option B, you'll end up buying cars designed, tested and built elsewhere once they have proved to be reliable and useful (so fewer local jobs and businesses and you get to live with unsafe vehicles longer so more people dead or injured.)
It will happen. It might not happen where you live until somebody else has figured out how to profitably do it.