The square steel tubing that supports much of the undercarriage including the storage bins on the outside of the Barth, is indeed a weak link. In our '85 Regal, about 20% of it was seriously rusted. Tere scrapped every bit of it and put a rust proof frame paint on it. That's a temporary measure but it's held so far. Maybe someday, we'll have some steel tubing fabricated to meet the curves and replace what we have to. I've seen pictures of at least one Barth where the tubing was so rusted away that the storage compartments essentially fell off. The barth looked like a young man with knickers on If I had the money, I would have fiberglass strorage compartments designed and an entire aluminum substructure fabricated. Guess that's a little over the top.