See also:

Connecting headphones
You can connect headphones with a jack plug or operate them using the infrared interface. To enable optimal use of the infrared interface, use infrared headphones that comply with the IEC 61603 ...

The concept
The following can be operated using the buttons and the thumbwheel on the steering wheel: Current audio source. Redial on telephone*. Activation of the voice activation system*. ...

Controls
Controls 1 Volume, on/off 2 Change wave band 3 Change entertainment sources 4 Change station/track 5 Programmable memory buttons ...