Rarely is a trailer ever made out of 100% aluminum.  Generally some components are steel such as couplers and axles.  A trailer is generally considered aluminum when the frame and floor are aluminum.  Most steel framed trailers utilize a wood floor system and an aluminum exterior.  The advantage of aluminum trailers are a lighter weight and more weather resistant.  This makes aluminum trailers cheaper to operate and last longer.  An additional benefit is that aluminum trailers will have a higher resale value later in its life than a steel frame trailer due its durability.  These trailers are offered in open and enclosed.  Pace and Exiss offer aluminum car trailers.  The Pace Silver Arrow model is a line of aluminum trailer that Millennium offers.  Silver Arrows may been found by browsing our inventory of Pace Trailers for Sale.