If where talking about the same thing the easiest thing to do is tap into the rear speakers near the speakers. Im not sure if you have a CC, or ext cab but you definatly have rear speakers. If your trying to wire the converter then just pop the rear plastic off. That way you dont have to but 10+feet of RCA and try to run them. Plus the wires arent easily marked.
Is this like what your lookin at?
LN60 - Car Audio/Stereo - Car Audio/Stereo Accessories - Legacy Car Audio - Legacy High Level to RCA Line Converter
I tapped into the speaker wire in the pillar between the two doors in my CC. Then ran speaker wire to the little converter under the rear seat.
