I've got a problem with VYII Calais factory audio system. Had dramas from the start beginning with finding factory head unit but found one and installed it. No sound from the back at all. Piss farted around chasing wires etc, seat and shelf out. Eventually found the sub amp in the boot with a blown fuse, thought beauty, sorted. Was great for an hour or so, but now no sound from the rear speakers in the doors? Anybody have any ideas on where to look? Anybody have a wire diagram for audio in the Calais? Thanks heaps in advance.