A plenum assembly for a vehicle includes a plenum body, a plenum grid coupled to the plenum body, the plenum grid including a grid surface having a plurality of grid openings and a separation member extending from the grid surface toward the plenum body, and a vent port including a side surface extending from the plenum body and a domed surface formed integrally with the side surface, the vent port including an edge defining a vent port opening in the side surface such that a flow of air passes through the vent port and through the plurality of grid openings in the grid surface.