Well if you have to run all new wiring this is how to do it and make it easy on yourself.
First of all break out your number one best buddy, your multi-meter.
Find a power sorce in the fuse box that is on all the time. Weither the key is on or off. Splice into that and run the wire to the Memory wire on your aftermarket deck. It will mostly likely be yellow.
Next find a power source in the fuse box that is only hot when the ignition key is either in the "run" position or the "accessory" position. Wire this into your red power wire on the deck.
Find a suitable ground and ground the deck.
Now this is where a good multi-meter comes in. Of that big mass of wires either 8 or 12 (depending on weither or not you've got the 6 speaker "premium" sound option) of those wires go to the speakers. Set the multi-meter to test for contanuity and start probeing the wires. When you get a tone from the multi-meter, those are the two wires to a speaker. Fade the deck all the way to the front and to the right. Wire the speaker into the deck in the "front right" postion and see which speaker the wires go to. Once you've determined which speaker the wires go to, wire them to the appropriate wires on the deck.
Then your ready to listen to some tunes
-Josh, aka the tireburner