Rust cannot be pressure-washed off. Removing it is a lot of work and requires the use of special chemicals. It this coach has never been used, I would question why it has so much rust! That would be a red flag to me. However, if the rust is removed correctly and a rust retarder is painted onto the axels, etc., that would probably be OK. It's what is inside those axels that is more important, but either way, I would want the rust properly removed. Few dealers will want to do this because it is expensive and time-consuming. If I had a choice, I'd pass on this coach.