Of course it can be turned off. Just not by you.
The average 2018 car has about 30 microprocessor controlled “electronic control units.” Some luxury cars may have as many as 100.
Have you found the “off” switch for these in your car?
You expect them to let you “opt in”?
Google reads all of your inbound Gmail as well as the emails you write AND the drafts you wrote and didn’t send. That data is cross-correlated a zillion different ways to everything you do on Google.
Just wait until the car data is purchased by Google and it’s munged with everything they already know about you.
Doesn’t this data have to be broadcast out by the vehicles OnStar,etc. system?