While I agree with your point about the lack of full integration, the turn-by-turn subset of functionality is largely provided should you happen to be using Waze. It gives you an audible and visual clue at about upcoming turns in the head-unit (I have personally set my Waze voice to Cookie Monster, and
I my kids absolutely love it). It's not in the HUD which I agree would be nice, but it's nevertheless roughly not far from eye-level. I have other issues with the Waze integration however:
1. You can't see song titles with Waze up. If you happen to be using Spotify you will quickly see the song flash along the top line when the song changes, but if you happen to be on a radio station, you've got to exit the Waze map and exit
Android Auto completely to see that.
2. I haven't found a way in Waze to lock North to the top position. I don't want to be the center of the world with the world rotating around me. Keeping maps oriented correctly helps me learn a new area if I'm exploring.
3. Waze doesn't give general background geographical information, for example the name of the
speed-trap small-Texas town you happen to be driving through where they dropped the speed limit from 75 to 45 in about 100 meters.
4. Turn-by-turn in the HUD would be nice
5. Why doesn't Waze support reporting of police from their voice menu? It's explicitly excluded.