I would be a little skeptical of the dealers refusal to let you have it checked out...and I have not heard of the 10 yr rule...mine is 10 yrs old, but I have taken care of it since I bought it new...don't think I would trust the people who have it..seems to me he may know something he don't want you to find out about...as one person said...there are thousands of RVs out there and probably some good ones, waiting to be bought...shop around and don't jump on the first one...just my advise and I have been doing the RVing quite a few years...good luck