The rears aren't wired with any of the front speakers. If they were, the fader wouldn't work.
The footwell speakers are woofers. Disconnecting them will remove the bass.
The tweeters I added are in parallel with the midranges in the doors. Combined nominal impedance doesn't change much as there is a crossover. The woofers are probably also in parallel with another first-order crossover.
Typical schematic (not BMW)
http://freecircuitdiagram.com/2009/01/02/1st-order-3-way-crossover-circuit-design-using-free-online-tool/
BMW may have left out the inductors to save money.
I have a set of BMW wiring diagrams, but they only go to about 2007. So no e89s.
The footwell speakers are woofers. Disconnecting them will remove the bass.
The tweeters I added are in parallel with the midranges in the doors. Combined nominal impedance doesn't change much as there is a crossover. The woofers are probably also in parallel with another first-order crossover.
Typical schematic (not BMW)
http://freecircuitdiagram.com/2009/01/02/1st-order-3-way-crossover-circuit-design-using-free-online-tool/
BMW may have left out the inductors to save money.
I have a set of BMW wiring diagrams, but they only go to about 2007. So no e89s.