Thanks a ton Rich! I'll try to keep everyone posted with all the details on the wiring and drawings and stuff of my progress :P If anyone chooses to repeat my mess
For those who may be remotely interested - I'll be ripping out the stock speaker wiring and putting in two speaker sets, got Infiniti Kappa Perfects 5.5" as a compete 2-way set in the front, A/D/S 320i/s complete set for the rear, and the A/D/S 6-channel amp to power the 4x individual 2-way crossovers and the subwoofer. I'll rip out the stock wiring harness and run the 6xRCAs to the amp, and the just four sets of wires to the crossovers and speaker wiring form that. I'm hoping to 'connectorize' everything short of the RCAs and make it modular. Might even use the stock speaker connectors soldered to my 'aftermarket' wires. Instead of my A/D/S 642 CSI crossover, I will just use the Pioneer DEH-80PRS to take care of all the crossover in the pre-amp outputs. It sounded great with a good quality headunit as-is but I want to make this amp system more modular and solid, and so that it stops moving around my trunk :P
I'll report on the audio quality and so forth after the system is complete.
I also got a thread going on electronics for the cluster. I will be working on all that stuff during the last week of May/First week of June, so expect to see an update with pics around that time.
Cheers,
Artem