I drive a Cupra (a Spanish brand, a spinoff of SEAT, owned by Volkswagen) and when I was driving my car out of the dealership I had to tell the salesman I was not interested in signing up for the free app they were trying to foist me. He was dumbfounded. The model was selling like hotcakes yet I was the first customer that had outright refused to sign up for their shitty app. They pulled off the inevitable switcheroo, it now costs a monthly fee and I don’t want to think about what insidious things they can do with it.
Chances are the dealer and manufacturer can still get telemetry data through the cellular modem built into the car. You will need to remove it to be reasonably sure that data isn't extracted.
The issue is that data is also shared with third parties, such as insurance companies and possibly the government. I could not, in good conscience, drive a car that spies on me and can be effectively controlled remotely.
