One of our requirements when shopping for an RV was to have room for our cat and dog (kenneling pets during vacation was a pain, and expensive). We ended up with the
Bigfoot 25B17FB, and decided that the cat's liter box could go in the wet bath (just set it outside when it's time to shower). Installing the "2-way Interior Cat Door" from Pet Safe was really easy. Be sure to tape up the door, and use a fine tooth saw. The directions say to drill a 1/2" hole in the corners, but after the first hole tore the door finish a bit, I didn't drill the second hole right on the edge. I found that the fine tooth hacksaw blade on a `pusher' handle worked best with the laminated hardboard of the door. I recommend a file to finish up the edges. I was worried about moisture swelling the hardboard, so I used liquid nails on the cut edge, and caulked around the interior with a locktite product that dries clear (leftover from some previous house project). I'm not too impressed with the door quality, so if this deteriorates I'll have an excuse to make a real wood door. For now it works nicely. The wet bath door is just a smidge too thin for the cat door, but the interior caulk covers it up.
Thanks,
Alex