There is always a choice
about methods of tracking. The vehicle could report its miles when connected to a recharger and not have to expose the drivetrain systems to wireless. There are also other protocols aside from 'ethernet' and they do not exist on inexpensive mass-produced circuitry. DECnet is an old one but consider it as a robust example. It can be made to use the same physical stuff but it won't go through an ethernet router at all.
Real time tracking of everyone vis some kind of universal wireless system would present advantages for those who know how to use a coaxial switch. cloaking device engaged.
It'll be a long time before the government starts road-taxing amything that is touted for ecology.
I'd bet that the miles will eventually be reported when recharging. Its simpler and most homes and businesses have access. It would also be harder for EV drivers to hide miles because the same computer that talks to the charger would be handshaking with the 'odometer'. The whole thing could be used to keep track of data for the manufacturer's warranty and service interval requirements.
