wires for rear harness

[mgd420]

I have a 2005 vibe, no upgraded sound package. There is a wiring harness in the rear right that seems to be for a stereo upgrade. I would like to tap into this for high level inputs for a sub. Does anyone know which wires are which in this harness

[WaveAction]

i believe those wires would have been for the upgraded sound package for the sub..atleast from my understanding