A niggle I have had since picking up the car is that android auto is very quiet to the point that it needs to be near full volume for any decent sound, I have found a fix of sorts which makes a huge difference. It’s as simple as switching to media or radio and enter settings, select volume and change the volume increase with speed to max, by default this is set low and changing this has made a massive difference for me.

 

I noticed the same thing myself when I started to use AA. (AA is not yet officially supported in FInland but I installed it from ApkMirror). I don't remember exactly what I did to get decent sound levels, but as soon as I had it fixed, the problem disappeared. It may be that when I first used AA for music (Spotify), the volume level was very low, and the volume dial on the steering wheel only increased the volume to a very modest level but the volume dial on the radio went further than that. Perhaps the system now remembers the maximum volume I used as allowable.