Cut the back panel support bracket so the radio mounting tray could slide through, drilled out the holes for the drop down fuse board, as this had to be shifted to the right slightly as the radio rack was up against it. Screwed my new air vents in place just to have a look up against the new panel, well I'm happy, they look great. With the panel all in place I found I need to cut a bit more out the bottom of the slot the radio fits into, as at the moment it is twisting the panel just slightly, not noticeable but I know.
