I do remember talking about routing CAN messages over wireless in automotive standards meetings about 20 years ago. You would need to do something like this if

I do remember talking about routing CAN messages over wireless in automotive standards meetings about 20 years ago. You would need to do something like this if we wanted to increase traffic density by creating linked "road trains" of cars that would all brake together. There was also the feeling that California might require a wireless connection to be able to do continuous emissions monitoring.