I started putting together all the info. you need and it's fast becoming a large collection of files.
It might be easier for you (and more informative) if you can get the BMW Tech WDS site running on your computer (Windows is best).
WDS BMW Wiring Diagram System - X5 E53
You'll need Java and the Adobe SVG plugin. You'll also need to set a Java security exception for the bmwtech.ru domain/website.
I can tell you that the pin out you have in your first post is essentially correct.
The Amp. in the left side pocket is called module A18.
X18771 = 15-pin (black)
X18772 = 18-pin (black)
X18773 = 26-pin (blue)
See the attached PDF for details (virtually the same as your list).
The Radio in the boot is called module N9. The main connector on this is X18126 and the connections on this vary from year to year.
The main display unit is module A196.
It has two connectors - X18801 and X18802. Wiring details are in another attached PDF.
Both X18801 and X18802 have the same pin layout (shown above).
I can provide wire colours to go with all this data, as the
BMW Tech WDS site has this data on the actual circuit diagrams - sadly the colour data is not in table format.
Hope all this helps ya!
