My wife's 07 Equinox didn't come with the 7-speaker system... so I'd like to add the factory sub, at least the factory enclosure so it looks stock, and the dog probably won't destroy it.. aside from thieves looking in and stealing it... How is it attached? Is it part of the rear quarter panel? So I would have to replace the whole plastic panel, or is it a separate piece? I can honestly say I've never seen one in person, and no one seems to take pictures of it... so I don't even know what it looks like. All I know is the Husky floor mat we bought has a cut-out for it... so once I install it, I can trim the mat a bit to make it fit. And then... there's the wiring! I know most GM's don't come pre-wired for anything these days... so what wiring would I need to add? Is it fed from an amplifier somewhere that I don't have? I have no problem adding this stuff... just need to know where it is.