I wonder if this has something to do with the Boston system... Of all the threads I've come across with people talking about this problem, it seems they all have the Boston system... I was pretty concerned with this issue when I went to install my system, but I do not have the BA option in my car.
I used a PAC SOEM-T LOC and tapped into the rear speakers to get the signal. I chose the SOEM-T because also provides the signal to the remote wire, as I didn't want to try to run a wire to somewhere else in the car with keyed power to try and get the remote signal to the amp. IIRC the SOEM-t can detect as little at .5v through the speaker wires and provide the remote signal to the amp... Although it seems like a good idea, it also seems that there is always at least that running through the speaker wires even when the radio is off... So even with I turn off the radio, my amp is still powered on. Is this a big deal? I don't think so, but I don't personally know if it will damage something eventually.
Long story short, I do not have the BA system, and the p/c/t I was so concerned about going into this installation is not present, so I am happy. Like I mentioned, the only thing wrong with this set up is that the amp is always powered on with the ignition is on, even with the radio off... But with the ignition off, the amp is off, until the radio is turned on and then it powers up... No big deal... I think?
My system install thread is here:
http://www.camaro5.com/forums/showthread.php?t=191938