I just bought a 2006 Mustang; the deck says 'Shaker 500', but I'm not sure what exactly that is. The prior owner had a custom system installed, and half of it didn't stay with the car. I want to bring it back to stock, but I don't know what that would be! I've only opened up the doors so far, but this is what I've got: -JLAudio Tweeters in the door card -The bigger speaker at the bottom is also JLAudio Is that the stock setup? I'm missing: -the center speakers in the door -also, I don't seem to have a wire to the lower door speaker, but it looks like there should be a pigtail harness for it, coming out right near the harness for the center speaker. Any help/advice is appreciated.