> We also found a number of vulnerabilities that allowed us to, with physical access to the vehicle, to gain root access to two of the infotainment systems

You should not have to depend on vulnerabilities to gain root access to a computer you own.

I'd rather like to see e.g. a system protected by a unique ECC SSH key, and you get the copy of the private key in paper together with your manual, as well as instructions on how to regenerate it.