I'm not aware of anything that you can do to enable Apple Maps in the HUD. The heads up on my experience is pretty limited and as far as I know only truly integrated with the head unit and dash.I'm not sure if this is the right forum for this, but since there are Volvo OEM personnel lurking ...
Is it possible to enable/display Apple Maps guidance in the HUD while using CarPlay? if not now, how about in a future release?