Abstract: A metal trailer interlocking panel attached to a trailer frame used in the construction of an enclosed or paneled trailer, preferably in a horizontal and stacked orientation, includes an upper groove assembly and a conforming and interlocking lower groove assembly, an inner surface welded to a vertical trailer frame member and an outer surface having a lower slot member and an upper slot member forming a sliding channel within which is slid a horizontal outer panel insert riveted to the panel. In the event the panel insert is damaged by hail, road debris, branches or other accidental means, or a simple change in aesthetics or display medium is desired, the panel insert may be exchanged without requiring replacement ofthe panel.