https://www.engadget.com/motor-vehicle-data-question-1-081059455.html
Car Companies Argue That Right-to-Repair Law Is Unconstitutional
https://www.vice.com/en/article/g5q5zq/car-companies-argue-that-right-to-repair-law-is-unconstitutional
One claim I have heard, without trying to track it down, is that with respect to tractors and such, a very large percentage of the "repairs" involve disabling emissions control devices in order to get a machine running again. I don't see that as a prime motivator for passenger cars though