This is the part I have been most curious about. How does the data get exfiltrated. Here is their link to explain the different levels of car connectivity.

https://privacy4cars.com/data-in-cars/p4cs-five-levels-of-ve...

According to that link, the majority of cars on the road are currently "level 1." Which can connect to phones, but cannot use them to "phone home". But that is of course changing with the cars sold today.