I researched this a bit, today, while driving. Background— I usually use Apple Maps (because I like its presentation better) but I have and use both Waze and google maps as well.
I am using Apple Car Play.
On the HUD- I could only get Apple Maps nav info there: when navigating (on the screen) with Waze or Google Maps the HUD just showed a compass.
However, both Waze and Google Maps worked just as well as usual on the 9” touchscreen display/audio.
I am sure from Android Auto you could get either of those two on the HUD.
I am surprised, though, that apple car play didn’t put the nav from the app I was using, in car play, onto the HUD. But maybe you’re right and it needs some update or other.
(I’m thinking I can put Apple Maps’ directions on the HUD and Waze on the screen-)
Anyway- hope this helps.