HiFi/Navigation: Anyone do English ??? Cannot find Answers

[silver50]

Greetings from Edinburgh, Scotland.
Searched other forums but I just cannot find help for these questions!

I am desperate to upgrade my hi-fi system. I used to have Logic 7 Professional in 745i

Here at 7er Forum is where answers are. I have a 2006 730d Sport

1. I have Basic "BMW Speaker System" NOT "Hi-Fi Speaker System" Do you know excactly how front speakers are wired regarding the under seat woofers? I am thinking about fitting Blaupunkt "PnP" Amplifier and want to know if the under seat woofers run independently from my CCC player or if there is just one left/one right speaker cable from CCC.
 http://www.blaupunkt.com/uk/7607792132_main.asp

2. I have heard the speaker cable is in place in each rear door. If so, can I find these cables in trunk/boot(maybe where amplifier for Logic 7 is???)

3. Any help or suggestions for upgrading basic stereo in E65 much appreciated!

Many Thanks