Stereo questions for 2000 C43 (W202)

[C43AML]

I just purchased a 2000 C43 with the Bose stereo upgrade. While the highs and mid-ranges are fine, the Bose system lacks decent bass (as usual). I have a 10" ADS sub and amp that I can add, but I have a few questions maybe somebody can answer.

1) Where can I get a schematic of the Bose system for this vehicle that shows the locations of the wiring, speakers and amp(s)?
2) Has anyone else added a sub to this system? If so, where can I put the sub and amp to not affect my ability to use the fold-down rear seats? Also, I need to be able to remove the sub and amp at some point since this is a lease vehicle.
3) If I decide to upgrade the speakers and add another amp in the future, what would anyone recommend to maintain the stock enclosures and allow me to remove the upgrades at time of lease end?

Thanks.