Anyone know about Impala's wiring?

[SinisterSounds 0]

I recently picked up a 05 Impala, and due to a problem with my other car, am stripping out the wiring kit in it to throw in the impala. I have an Aftermarket deck in my other car (A Grand Am), but I believe it has a short or something thats screwing up my electrical system >=(

Anyhow, I had a buddy do my wiring on the Grand Am, and since I didn't have a precut hole in the firewall, he ran it by the side of the door. Only problem is, in Arizona, the heat and weather is horrible, so the wire is hella faded and looks like it is being rubbed or something. So obviously I'm going to need to replace that.

My question however is : Is there a hole already in the firewall that will make it easy to run wires, and secondly, how would I go about hooking up an amp kit to my factory radio? I have the Onstar equiped system, and steering wheel controls, so I don't want to screw anything up and lose those lol.

Oh, and as for what I'm running, i'm designing a box for a 15" XXX (the older one with XBL), and am going to have it firing into the cabin through the rear fold down arm rest :-D Pleasure to be here guys, and hope to learn a lot and hopefully help where I can!

Alex

[ford302redneck 15]

Take it to somebody who knows what there doing then?

[SinisterSounds 0]

Take it to somebody who knows what there doing then?

Yeah, only problem with that is that I priced around. $80 to install an amp kit at one clear across town, $75 to install at a local store, and $100 to install at the other two car audio shops around here.

I'm strapped for cash right now, and when I asked what about if I ran all wiring and they did the 'finish' behind the dash, I was still quoted over $75.