I'm thinking they bypassed the Crossfire amp completely and they're running the speakers off the amp in the head unit. That would be very easy and eliminate such things as figuring out which wires were which going into the head unit... I bet if you open up the floor and look at it, that's what you'll find. Or I could be wrong - in which case, you could take a big picture with that nice camera of yours (set on close-up) showing the wires going into and out of the factory amp...