The days of single- and double-DIN stereo swapping are slipping away fast. You're pretty much stuck with what you get when you buy the car, so it had better be what you want.
For the other car, though... no way, no how. It is stuck with what it has. Its touchscreen is a nonstandard size, seamlessly integrated into the dashboard, and not used by any other cars AFAIK. Fortunately it's also pretty good. It supported wireless CarPlay from day one, and it isn't from a manufacturer that relies on fracking its own customer base for $20/month. Safe to say nobody will be building an aftermarket replacement for it.
We use CarPlay with our Mazda. The heads up display on the windshield displays the next turn information from Apple Maps.
Edit: it looks like Lineage has support for Android Automotive: https://lineageos.org/Changelog-30/