Hello Mark. I am sorry to read of your plight, Bearing in mind the caravan you are trying to PX is 12 Yrs old, it would not be uncommon for damp to have occured. Check the purchase details of your caravan, was it sold to you last year with any warranty about damp? Did you comply with the terms and service/ inspection and arrangements of the deal, IF you did and teh damp has occured in the last 12 months, then you may have some leaverage,but realistically I don't think you have much chance of redeming the situation unless you want to go to a lot of effort, which may cost more than the value of the caravan. However If you could have the caravan surveyed by an independant engineer, and have a writen report, If this shows the caravan to be dry, (bear in mind that it may be damp)then you could approach the dealer again with the evidence and ask them to reconsider. If they refuse and maintain the caravan is damp, then you could approach the trading standards office about the quality of workmanship (i.e. the survey the dealer carried out). This is messy and I wouldn't hold out much hope. Best suggestiopn is to sell the van privately (you may get more than the dealer value anyway)then with the extra cash negotiate a better discount for no PX.