The version in Volvo and Polestar's is actually Android Automotive, which is it's own Android distribution with it's own version of Maps/Spotify etc. Funnily it even has Android Auto functionality too.
Although it didn't use to have Android Auto, which was awful. Because as you alluded to, Android apps are not automatically available on AAOS. As it happens the music app I use is not available on AAOS, so until Volvo added Android Auto support to their cars I could not get a good experience with my music.