These is a really good breakdown.

I agree that the Business CD is not bad. I actually don't have a problem with the sound quality of it. My issue is I need navigation, iPod control, XM, yada yada yada. So the factory system has to go.
I don't have much experience with installing amps and I was just trying to familiarize myself with the basics. I have never seen anything quite like this factory amp setup.
The question about connecting the speakers in parallel was just me trying to figure out how can you push 10 speakers with a 4-channel amp? I figured you would have to connect multiple speakers to one channel. But if you did it in parellel then you could exceed the ohm capacity of the amp. I now understand that passive crossovers will take care of this issue.
By the way, I have the standard lift-out floor.
I would say that my system needs are fairly light. If the factory system had decent navigation then I would have gotten an X5 with navigation and just upgraded the speakers. With that said, I don't mind paying $2000 for a good music system. I have already paid over $2000 for my Pioneer components along which include the AVIC-Z1, GEX-P10XMT (XM, XM NavTraffic), CD-IB100II (iPod controller), and ND-BC1 (backup camera). I am not the kind of person who buys a $60,000 car and then skimps on the music.
As you can probably detect I am a DIY kind of guy. But after reading this write up I have decided to let the pros install my system.
If you were in the Phoenix, AZ area I would look you up. Can you recommend anyone in this area?