There's an interesting contrast between the (traditional) automotive and today's consumer electronics industries; ever since the early days of cars, manufacturers have tolerated and even encouraged the growth of a large aftermarket parts industry, to the point where you can build an entire "Chrysler", "Ford", or "GM" driveline from the engine to the wheels with entirely non-OEM parts. Of course, the manufacturers themselves will sell parts to anyone who wants to buy them.
Contrast this with companies like Apple and Tesla, who attempt to maintain tight control over their products and use legal action against those who want to "open them up".
(From what I've seen, European and Asian automotive companies are somewhat less open, but once again there is still a large aftermarket.)