Originally Posted by deso
I ended up connecting the bazooka to the 12v constant and remote turn on at the amp using the Bose wiring diagram. For the signal, I cut the RCA portion of the harness and split the wires. Then, I used wire taps to connect the split rca wire to the sub harness (blue/brown & blue with white stripe/green). I don't know much about car audio but this seems to sound fine to me.
As long as the Tube and the factory stereo are playing, you are fine. When you are experiencing an impedance problem the Tube and the factory system will stop playing for what seems like no good reason.