See also:

Activating HDC
Press the button; the LED above the button lights up. ...

Adjusting volume
Turn knob 1next to the CD/DVD player until the desired volume is obtained. You can also adjust the volume with buttons on the steering wheel. ...

Display visibility
The visibility of the displays in the Head-up Display is influenced by: Certain sitting positions. Objects on the cover of the Head-up Display. Sunglasses with certain polarization filters. ...