Most RV's in the desert SW that are not under cover look pretty dull and bleached after 10 years. That sun and heat can take a dramatic toll on the roof and sealants (more prone to leaks), rubber/plastic trim, paint, not to mention the cooked decals.
Most trailers I've seen that spend most or all of their time near saltwater have noticeable amounts of rust and corrosion on the frame/chassis, metal trim and attachments, and the exposed a/c roof components after only 2-3 years.
IMO, RV's located in the mid-west, or more northern climes, away from the coast, tend not to deteriorate nearly as fast.