Many new RV's have a major flaw. They use a new single piece roof and flexible sealant. Sounds good right? Spoke with a dealer I haul for recently about the soft sealant they are using on the new trailers. 05 and 06 This new sealant is used on the one piece roofing material that is some synthetic (plastic single sheet for whole roof). I was very impressed because it is quite flexible and asked about it. What he told me was shocking. This new sealant will dry out and crack and leak sometimes in as little as 3 to 6 months. They look at it as a new profit area since so many people do not know about this and fail to safeguard against it. By the time the owner finds out sometimes internal damage has been done and additional work is needed. Many just trade in and those that choose to have repaired face a big (profitable) repair bill. When I asked him for a solution here is what he said. " We reseal the enitre roof with a product we get from our motor home supplier that sells us their high dollar units $ 500,000 and up. From the factory they come with a similar sealant but quite expensive per tube. He buys it and uses it for any repairs on these trailers, if the customer is willing to pay for it. If not he declines to make the repair since they will be coming back with complaints. I am not sure how many companies are using the substandard stuff but the dealer said most of the less expensive units are coming in with substandard sealant. Have not talked to any other dealers about this solution, but a number of them have agreed that the sealant is not as good as it should be. Anybody in the industry who knows more about this who would like to chime in ? R C :--)