I took my underbelly off to add a second fresh water tank and was also dismayed at what I saw. While I didn't have anything as bad as tanks falling off, I was surprised at the sloppy workmanship. Wires loose everywhere, one duct crushed and split, trash left behind, holes cut into floor much bigger than needed, etc, etc. Like others have done, I took the opportunity to improve everything I could. I posted a few pictures of some before and after of the wiring and the redoing of the ductwork. I now have 100% PEX tubing (no more braided at all) and insulated the water lines. and The structure quality of my trailer is top notch and now the rest underneath looks as it should. It should be pretty trouble free from now on.