Question about adding subwoofer in trunk of '03 320CLK
 

I bought a 320 CLK 3 weeks ago and love it. I have found the Bose system lacks low end badly so I was thinking about adding a powered subwoofer to the system and mounting in the trunk. I did some research and found a small unit that has been given great reviews by people that have added this unit to smaller cars.
First off, can I use the wires going to the center subwoofer to send a signal to the powered subwoofer? Would I need to use splitters and keep a signal going to the Bose speaker? Second, can I just power the subwoofer off of the battery since it is accessable in the trunk?
Any thaughts, concerns or suggestions would be appreciated.

This is the unit:
http://www.amazon.com/Boss-BASS600-L...ance_ce_ai_BST

These are a couple of threads from another forum discussing the unit:
http://www.northamericanmotoring.com...subwoofer.html

I found this link to get information about accessing the rear Bose subwoofer (for $4.95):
http://www.carstereoremoval.com/htm/...brio98_03P.htm

http://www.northamericanmotoring.com...subwoofer.html