[Andrey originally had pictures of pages from a PDF, containing the installation instructions for a Subaru OEM harness -- used to install the Navi HU in a car that shipped with a non-nav HU. My reply was referring to that document. The current picture is one of my older transplant harnesses.]
That kit was only available outside of North America. Even in the countries where it was offered (Australia and Europe), Subaru no longer offers it. When people in those countries asked their dealers a few years ago, they were told that the harness was not available as a separate replacement/repair part.
Also, your USDM 2009 may not have the 15-pin "OP connector"
(which provides several signals that the nav HU needs that are not available on the factory radio harnesses).
All is not lost. See this
. BTW, from there I link to a PDF version of that OEM install document.
Also see your earlier thread: 2009 WRX NAVI question?