[stuart78]

The in-dash systems these days do a lot more than they used to. Mine (VW Atlas) has 50% of the temperature control, all vehicle settings, etc baked in. All could theoretically be maintained and upgraded, but these are not really separable from the car itself.

I like the idea of them being upgradable, but it would seem to depend on more software and API discipline than I imagine VW or any the other manufacturers being interested in.

Relatedly, the lifecycle of a lease is much closer to a phone, so for owners of the 30%[1] of cars out there that are leased, the upgrade cycle will presumably keep them "up to date". If the car manufacturers are pushing us more towards away from ownership (analogous to phones, software, etc.) then there is little incentive for them to make significant investments in upgrade-ability. And like legacy phone hardware companies, they are too busy preparing new phones to give much love to upgrading older ones.

[1] https://cars.usnews.com/cars-trucks/buying-vs-leasing

[SmellyGeekBoy]

They're just industry standard CANBUS signals sent over a wire, there's no technical reason a third party head unit couldn't support all this extra functionality.