Hey peeps... So My Install is underway and I should complete it today (Tuesday) with a little help. It's the Z1 going into an 06 WRX..
Nice car, maybe tillithz has some spare parts for you.... 
sorry, that was cruel.
I'm going to back the train up a little here and try to better understand the basic wiring concept needed for this install:
there is a wire harness coming out of my car
I don't know about the WRX, but yes, cars usually have a plug (some times many) going into the radio.
The Z1 comes with two wire bundles 1 says power supply and one is RCA's
Actually there are 3, the power supply one and 2 others, labeled on the back of the Z1 (connector 1 and connector 2). I think both have regular wires and some RCA's.
I bought the appropriate wire harness from circuit city for my exact car, that has two ends on it, one that matches up to my car, and the other side I'm supposed to cut off.
Really, they give you a wiring harness which has 2 ends? Did they give you what that harness was supposed to plug into.
One end plugs into the car (the end that came out of the radio) and the other end you just cut off? Was it supposed to go to something else?
Generally the wiring harnesses you get from places like that have the mate to what comes out of the car and it just ends with wires dangling.
After I cut off the one side of the wire harness I bought,
Then you are left with something that mates to the car's wiring and ends with bare dangling wires... right?
WHAT DO I HOOK UP TO IT? the power bundle? or the RCA's?
Well, it depends on what wire it is. Generally most aftermarket harnesses will have color codes wires with (generally) standardized colors for what they do or where they connect. You have to match them up with the color coded wires on (possibly) EVERY connector in the Z1. It really depends on what the wires coming from your car are.
If you only have power, ground and 8 speaker wires, then those all connect to the power supply connector on the Avic.
But if you have, lets say a backup alarm (for when you get close to things) and there is a wire that goes to the cell phone mute wire of a radio to mute the radio if the backup alarm goes off, you hook that to what ever wire on whatever appropriate connector is on the avic.
So basically you look up every wire in the car's wiring harness (either through the schematic of the car itself, or what most people do use the sheet that is supposed to come with the adapter harness) and match each wire to it's corresponding one on any of the Avic harnesses. If when you are done you only use 1 connector on the avic, then that's all you plug in. If you even use 1 wire from (lets say) connector 2, then you should plug it into the avic as well.
and how do i do so, with butt connectors?
The best way is solder and heat shrink tubing. It's not too hard and will give you the absolute best connection.
If you can't do that you can use butt connectors, but I never recommend them. That being said, I'll bet 1/2 of all avic radios are installed this way.
But you want some form of physical connection, not just electrical. If you twist the wires together, you gave it an electrical connection, but if you pull hard, they untwist. You can (and I have) taken a crimp and squeezed it around 2 wires twisted together. And then wrap it in electrical tape.
But solder and heat shrink is the best.
Also, How do I correspond the wires I'm hooking up with what is in my car wire harness?
Are they supposed to match up?
Yess, you need to follow the car's schematic or the sheet that should have come with the aftermarket harness.
Anyway, I'm trying to get the "Big picture" here, I'm still foggy on the concept...
I swear, I am not completely retarded or disfunctional in anyway!!hahaha
I hope that helped.
I think he liked his car more than I do!!