Bluetooth works fine (or should work fine) with music, podcasts etc. I do it now with a phone, it’s a standard I don’t see why a mobile device running Linux would be any different.
As for maps, the voice goes over Bluetooth so I don’t see an issue there either.
I find car play awful. So I guess there us that. Half the time it does something stupid or the screen gets strange or a bunch of other problems like forcing my nav map when I want a different one.
What I want is true screen casting with touch feedback. That’s it.