It violates privacy, raises health safety issues (like home Smart Meters), and may lead to car manufacturers refusing to share data with repair shops not affiliated with the manufacturer. Many cars already spy on us and all are expected to do so within a bit more than a decade.
(From Roll Call)
If you’re driving a late model car or truck, chances are that the vehicle is mostly computers on wheels, collecting and wirelessly transmitting vast quantities of data to the car manufacturer not just on vehicle performance but personal information, too, such as your weight, the restaurants you visit, your music tastes and places you go.
A car can generate about 25 gigabytes of data every hour and as much as 4,000 gigabytes a day, according to some estimates.