I have a 2004 XJR with at least one blown subwoofer driver. Does anyone know how to get to them to replace them, either from above (remove grille) or from underneath in the trunk? While I'm at it, I might replace the drivers with a better quality drivers. Does anyone know the size of these drivers, the ohms, and a possible better replacement? Thanks in advance. It's the Jaguar/Alpine 12 speaker, 320 watt set up presently installed.