I heard that the reason the major car companies started to sour on CarPlay was because Apple started to get increasingly needy with their data collection requirements (as of CarPlay Ultra) and the car companies weren't comfortable (or legally able) to give Apple that much canbus/telemetry data. And I guess Apple was pushing CarPlay Ultra as the only option without classic less-data-snoopy CarPlay?
Heh, the version of this I heard from a Porsche tech was that the reason Porsche's supported Carplay (added in 2017 models) but NOT Android Auto for so long (added in 2022 models) was because Apple wasn't snoopy and Google was.
That explanation doesn't pass a sniff test if you even try to Google anything about car manufacturer data collection practices.
I find that hard to believe. My experience with Apple (as a developer), is that they are absolutely brutal about data collection, and being an Apple developer, means toeing a lot of lines, wrt privacy-related stuff.
It seems that every time I submit an update or new app, it gets rejected, because Apple just tightened the bolts a bit further.