Thanks, I've been working on an article about ipod and aux-in adapters.
This, like many other OEM adapters replaces the armrest cd changer. Since I have the OEM nav and a 2006, I use the armrest cd changer for music and decided it was too expensive to replace it with the OEM MDI adapter.
And FYI, the part number is 000, not the letter o. This is why I type the letters in my part numbers in lower case except for L. The correct part number is 000051446a (000-051-446-a). I have corrected your title.
For the searchers, here are the other part numbers:
iPod adapter: 000 051 446 c (standard issue on TDI except in Canada, 000051446c)
Mini USB adapter: 000 051 446 a ( 000051446a)
USB adapter - 000 051 446 b (000051446b)
aux-in 3.5 mm (headphone jack) - 000 051 446 d (000051446d)
I also see:
iPod adapter: 5n0 035 554 (5n0035554)
USB adapter: 5n0 035 558 (5n0035558)