First of all, I have the non-bose system, I believe. The stock drivers in the door panels and rear were 6.5" 4 ohm panasonics according to the label on the magnet and the deck does not have any bose logos. The factory deck was single din. The generic metra nissan maxima to pioneer harness adapter that I got from best buy also worked fine. I am the second owner of the car, the first owner was my mom.

When I was installing my pioneer head unit a few months ago I noticed a large black plastic box inside the dash that the speaker wires off the factory deck went into. I also noticed an amp turn on wire that lead to that seperate from the antenna power on. Is this some kind of amp? does the factory deck send low level to that along the harness or is the harness high level. I have been running my pioneer's high level speaker outs (non rca) into a harness adapter and therefore into that box in order to utilize the existing speakers. Possibly coincidentally, I blew a rear factory speaker (I believe I clipped it to death but I am not positive as I haven't removed it yet). I didn't bother to add one of my spare component amps yet so I was purely running off of the Pioneer head unit's internal amp, which naturally clips at high volume. I ran the factory system PLUS aftermarket head unit for about a month or more before the rear blew and it blew like 2 months ago so, other than that one speaker blowing, I have had no problems with the install.

Long story short, I was wondering what that black plastic box was inside the dash. Any thoughts? The advantage of using the stock speaker wiring was I wouldn't have to wire into the doors but just use existing wiring, however I wasn't sure if that wire goes straight to the door speakers or if it goes into some kind of line driver amp.

Second question:
What is the easiest way to run 14 awg speaker wire into the door panels for the 6.5's? I will be installing a set of higher end Peerless brand midbass woofers into the doors and I don't really want to use the factory wiring again as I don't want to blow any more drivers and I think the factory tiny *** wire sucks. Additionally I will be adding one of my spare component amps so having better wiring is a must.