What we really need is for all of the logs from a company like Uber or Google to get streamed to some third party.
All of the logs are encrypted (with different keys), and only when an issue occurs, the company who owns the data gives the key for that particular car at that particular hour for decryption. Basically a data-escrow.
This way we know the logs are not being tampered with, and we keep the data hidden from the third party.
These are test vehicles. If you don't let the engineers have access to the results of their testing except in the event of an accident, then we will never have autonomous cars.
Of course, maybe thats what you're arguing for. But either way, I think it's a bad idea.
All of the logs are encrypted (with different keys), and only when an issue occurs, the company who owns the data gives the key for that particular car at that particular hour for decryption. Basically a data-escrow.
This way we know the logs are not being tampered with, and we keep the data hidden from the third party.