The aerodynamic skirt assembly for attachment to a trailer may comprise a side skirt fairing, a rear skirt fairing, and a secondary treatment. The side skirt fairing may comprise an inner surface and an outer surface. The rear skirt fairing may comprise an inner surface and an outer surface and located aft of the side skirt fairing. The secondary treatment may be coupled to the outer surface of the rear skirt fairing, wherein the secondary treatment is canted outwardly at an angle from the outer surface of the skirt fairing and configured to redirect the air around the at least one rear wheel assembly.