I also have a Dice unit in the E46, which I plan on moving to the E39. I have both an 2006 E46, without NAV and a 2003 M5 with MarkIV NAV and I have added factor Sirius to both cars. The basic question is where is this iPod adapter supposed to be located? I believe in the dash near the glovebox? The long cable is probably meant to be run from the trunk when the CD changer is plugged in? The iPod adapter probably hooks to the Aux potion of the NAV unit and/or has some other cable connections to me connected. There may be different cables for the E46 vs the E39, however, the E46 with MarkIV NAV and the E39 with MarkIV NAV have a lot in common. That being said, if the previous poster is correct that he has seen it work in an E46, then it should work fine in a later version E39 with MarkIV NAV, which I believe you have. The dealership parts department needs to print off the instructions in the appropriate language for the country/area the accessory is being sold in. This is dues to BMW being a 'global' supplier and they do not include instructions with most of their accessories. It is called BMW Parts Aftersales Assistance Portal (ASAP). The parts department has a computer database with some specific name/acronym. Most accessories have instructions that are provided by the BMW dealership parts department. The part number does not show up in a basic Google search or on RealOEM, I believe this is because it is an accessory. If you look on Apple's web site they have generic information. This specific interface is something I have not seen before.

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