Update....I got my trailer back from the dealer. According to the service rep, he contacted heartland and was told the underbelly sag was normal. I asked him three times if he looked under the corrugated plastic to make sure the waste and water tanks were secure. He assured me that he did. I am not real sure about that as the bolts don't show any sign of recent tooling. I can only hope they did and everything in normal and tight. I also got my new trailer with a 1 foot square repaired torn section of underbelly covering. Black duct tape was used and the dealer told me it was that way when they got it. The service rep told me Heartland advised him to repair it with what he called "body tape." In my opinion, they should have patched it with something better than tape.