Background
I have a 2000 S-Type 4.0 with what I believe to be the Premium Sound package. In my trunk I have a large plastic shelf that is bolted to the rear deck, this holds 2 speakers and an amplifier.

I have successfully removed that plastic shelf/speakers/amp with no problems.

I have an aftermarket Alpine headunit installed.

What I want to do
I have an Alpine 600W amp and a 10" subwoofer/enclosure I would like to put in. I want to avoid running cables myself if possible.
Do you think it would be possible to use the existing amp cables to get audio to my new amp, what about the amp remote(to power it off)?
Does anyone have the wiring diagram for the premium sound amp?(I have looked online and at Captains but can only find stock)
I swear unplugging the amp has caused my tweeters to not work but I could be imagining things. Does anyone know how they are wired into the rest of the system?

Thanks
I have done lots of looking online and searched these forums and found all of you to be the most knowledgeable.