There are roughly 3000 rivets and at least 6 seams in an Airstream, and each rivet and seam can leak. The exterior shell will last a long time and thus the reason so many are still on the road. The floors are the weak spot in Airstreams and most over 20 years have had their's replaced. If they installed a composite floor then you would have a winner. According to latest news, the cheaper gas means they are producing something like 50 Airstreams a week while creating a 12-18 month backlog.
But aluminum trailers are hotter and colder than fiberglass
units due to the nature of their exterior walls transmitting the temperature to the inside. With white fiberglass
walls most of the heat is not transmitted to the inside.