So, I used the search like a good boy and can't seem to figure this out.. so I've come to the guru's.

This is on my 2004 Civic Si Hatchback:

Okay I got it pretty much set up to be installed, just need to go to the store tomorrow for double sided connectors for the harness but I've noticed that there are some spare wires and I can't seem to find a D3 harness diagram anywhere. From the d3 harness the light green, purple/white, and pink wires are homeless. and from the other side of the harness with solid orange wire is homeless (diagram from crutchfield says "illumination")

any help would be great

Your vehicle specific double sided harness will help with this also as they will be color coded to match the vehicle wiring as well as the h/u wiring, not all wires will be used.