If your car was specified with the Media Interface (which allows iPod, aux-in and USB connection on the Model Year 2009 audio units which have built in phone systems), you will have a MI connector in the glovebox or centre glovebox, into which you plug the appropriate cable set, or a different extension lead to connect to an iPhone/iPhone3G phone cradle.
This is the standard cable set for the A, B, C, CLS, E, GLK, SL. SLK class vehicles allowing connection of an iPod (or iPhone for music functionality), or a USB stick, or a 3.5mm aux jack for other non iPod music players.
NOT for MY2013 onward cars - see http://www.commandonline.co.uk/ntg4.5_media_interface_cables.html
This is the standard cable set for the A, B, C, CLS, E, GLK, SL. SLK class vehicles allowing connection of an iPod (or iPhone for music functionality), or a USB stick, or a 3.5mm aux jack for other non iPod music players.
NOT for MY2013 onward cars - see http://www.commandonline.co.uk/ntg4.5_media_interface_cables.html