blackview_admin wrote:

You should raise the conversation volume in your car settings (or by using the car buttons while calling)

Tried that, still not loud enough.

I think I've fixed this.
I unlocked developer options and ticked "disable absolute volume" for bluetooth.
Now, with all volume turned up to max (car and phone) the volume isn't too bad, still not great but ok.

Thanks for your feedback, i'm making this thread more visible.