External devices
Overview
AUX-IN port
Overview> It is possible to connect audio devices, e.g. MP3 players. Sound is output
over the vehicle speakers.
> Recommended settings: mid-level tone and volume settings on the audio device.
Tone may depend on the quality of the audio files.
Lift up the center armrest.
Connection for audio playback:
TRS connector 1/8 in/3.5 mm.
The AUX-In connection is in the center armrest.
Connect the headphone connection or line-out connection of the device to the jack
plug.
1. Connect the audio device, switch it on, and using the audio device, select
a track.
2. "CD/Multimedia"
3. "External devices" if applicable
4. "AUX front"
The volume of the sound output depends on the audio device. If this volume differs markedly from the volume of the other audio sources, it is advisable to adjust the volumes.
Adjusting volume
1. "CD/Multimedia"
2. "External devices" if applicable
3. 
"AUX front"
4. "Volume"
5. Turn the controller until the desired volume is set and then press the controller.
See also:
Exterior
The exterior remains the same for 2009, and the X3 retains its awkward
angles, disjointed taillights and odd lower bodywork. It's not unattractive, but
it sure isn't as stylish as Mercedes' new GL ...
Controls
Almost all functions can be operated in the same
manner as they are in the front. Special features
of operating the system in the rear are described
here. ...
What to do if...
▷ The current transmission position cannot be
displayed?
The vehicle is located in an unrecognized
region, is in a poor reception area, or the
system is currently determining the position ...