I'd leave the software to others, making sure to support both CarPlay and Android Auto.
Car manufacturers should engineer good cars.
Leave the good software engineering to good software engineering firms.
But I think that "car platform" should be clearly separated from the "userspace".
My sense is that why the legacy manufacturers are failing, at software, they have coupled the "userspace" to the "car platform". Updating UI in the center console is the same thing to them as updating the embedded code that controls the windshield wipers.
That being said, I admit you cannot fully leave the "userspace" to apple or google, because you, for example, probably have some custom kind of sunroof that doesn't fit in whatever generic APIs CarPlay and Android Auto offer for Sunroofs.
Additionally, if you go all in on Android Auto, you have no leverage when Google tries to extract more money.
At the same time, competing with Google or Apple on UX and continuity is a losing battle. When I enter the car, I want my car to continue playing the podcast I was listening to. No car manufacturer can do this, only Carplay/Android Auto can.
I guess the answer is to have good support for Android Auto/ CarPlay. But also have your own version as an insurance against being held hostage.
But Tesla shows that there are car companies that can build satisfactory entertainment software, which is not surprising as writing good software is something every car manufacturer need to do, considering how much software is used in a car.
They were in the news pretty prominently recently trumpeting their intention not to support Android Auto or CarPlay, but instead to roll their own system that they intend to monetize heavily.
Case in point, I have owned mostly Chevies through my life and have been mostly happy with them. But I won't buy the new ones because they've done away with plugging the phone in (or will in the future) and made their own. It's a cash grab to get our data and force subscriptions on us and I'm not buying it even if it's a good car.
The whole thing is absurd. We have to get a whole different car if we don't like a screen, but that's how it is now.
On a flip side - having one app instead of 10 would be nice…
I guess the sentiment for the rest of us punters and hoopleheads is, if we have to be rent-sook by one of them, at least CarPlay is likely to have a less-unpleasant user experience?