Discovered Mouse Highway
Like many here, I've struggled to seal up my rig to keep out mice, but they still occasionally get in. My last effort was to close up the slots for the entry steps. A month later, one still got in.
Well, today I removed my sliding storage tray from the rear bumper area (with helpful advice from this forum). Well, in the two back corners of the box/frame that supports the tray, were openings that expose 2-3" diameter round cut-outs in the cross member there. I presume to allow air circulation. A literal mouse highway into the underfloor area. In that very tight and awkward work space I managed to screw down screens over these openings. You need long arms or skinny shoulders to get this done (without drilling out lots of rivets to drop the frame for the tray).
With the drawer out, I also noticed large 1 1/2" gaps between the ends of the drawer frame and the fiberglass banana wraps on both sides of the frame. With a flashlight I could see the exposed open ends of the main box rails. Does anyone know if there are openings in these rails anywhere down the length of rig? If so, tomorrow I'm off to the hardware store to pick up lots of copper mesh to stuff into them.