Also, how much AI knowledge does NVidia actually have? They are big in computing hardware, not sure about AI.
For Amazon and Alphabet this is just about reaching a new market before the other guy. Things will be rushed, and they will move fast and break more things. I don't want to ride the car that was created by first-to-market.
I'm expecting that people in general are more concerned about other aspects of their cars, than the self-driving aspect (as long as it's there), just like people don't care much about what kind of GPS is built-in for a certain car brand. So I'm not sure that Alphabet would try to rush things.
Perhaps Volvo vehicles are the safest in the event of an accident, but the major benefit of a self deiving car is avoiding accidents altogether