Some embodiments are directed to an air intake grille assembly of a vehicle operable in forward and backward directions of travel across a surface. The air intake grille assembly can include a frame defining an opening. The air intake assembly can also include a plurality of louvers extending laterally across the opening, at least one of the plurality of louvers having a double curve shape defining first and second curve portions, wherein the first and second curve portions each have a different radius of curvature.