Ok guys, I just finished the install on my girlfriends 04 crossfire. I thought I would post this info as I found it very useful.

First, the Scosche harness is NOT a direct plug and play. You have to remove some wires. Look closely at the front of the harness and you will see that the pins have a small flange that you can squeeze with needle nose pliers. You have to figure out what slot is what, you should be holding the harness and looking at the pins with the clips on the right. The top row is (left to right)
A8,A6,A4,A2.
A7,A5,A3,A1 Harness clips
B8,B6,B4,B2 should be on
B7,B5,B3,B1 this side.

Ok so now that you know what is where, lets start removing wires. A1,A3,B2,B8,B1,B7 need to be removed.
Now on your radio harness you will need to find your speaker wires. Take the front right and rear right and twist the positive and negatives together, essentially making four wires into to. You will have to do this for the left side as well.
Ok so pay no attention to color wires, more importantly is the position on the harness.

Start with A4 this is constant power.
A7 is 12v ignition
A8 is ground. Please read your instructions from the radio to find the corresponding wires on your harness.
A6 is the illumination, turns on the lights when your headlights turn on.
A2 and A5 will now be twisted together and connected to the remote wire on the radio harness.
That should conclude all the wires in the A block.
The remaining wires are your left right positive and negatives, you will need to figure out what is what.

I hope this helps.