Hum22a

I have a avic-hd3 in my car. I think it is the same as a z3 in the us. I currently have a sub in my car which is connected through a line level converter, taking a feed from he rear speakers. This means I can't control subwoofer directly so was wanting to connect it through the avic directly. Has anyone got pinout to see where I should connect the RCAs as I haven't got wiring for the connector.