Ok, let me state it like this: Car repair consists of diagnosing a finite amount of components with known failure states and swapping them with known parts that

Ok, let me state it like this: Car repair consists of diagnosing a finite amount of components with known failure states and swapping them with known parts that are pre-approved and suitable for the car that's being repaired. Software 'repair' consists of managing thousands of dependencies and building new firmware from scratch. Modern cars contain a lot of mandatory safety systems, from ABS to emergency braking, pedestrian detection, emergency SOS calls, active steering with lane assist, speeding notifications, driver fatigue detection etc. Knowing how software companies operate, I presume they got it just about working per spec. I don't know if you can expect a third party to manage such a complex stack and update it in a way that's up to spec and satisfies all legal requirements. And even if that's possible I don't think it will be cheaper anyway. Computers are a very different world, just as car manufacturers are still discovering.