I wonder how aluminum will fare in those conditions. Because contrary to popular belief, aluminum can and will corrode too.
I've seen both painted and Aluminum trailers degrade in the salt but not in the way steel does. More like a pocked and scarred result than the dreaded "rot". I'm hopefull the newer aluminum panels will hold up but I'm taking a wait and see stand on this. The galvantic reaction between dissimilar metals can get real bad when salt is added.