Let the insurance companies figure out who to blame in each particular case; that's what they're for.
Just like every investor is fully aware of all variables when picking a stock, thus fully accountable in case of said stock's crash, correct?
I'd agree with the parent commenter: the car company would be responsible, financially. Legally, they would have to recall or disable all instances until a fix is pushed.
Human life, in this case, will get a price tag, instead of a (jail) time value, as is mostly the case today.