A motorcycle comprising: seat rails disposed above a rear wheel and supporting a seat; a taillight unit disposed on the seat rails for emitting light rearward; left and right side body covers (35L, 35R) disposed on the seat rails and covering lateral sides of a body of the motorcycle, the left and right side body covers covering the taillight with the taillight unit held between the left and right side body covers; a rear fender disposed on rear parts of the seat rails for preventing splash of muddy water as the muddy water is forced upwardly by the rear wheel; and a rear center lower cover covering a lower side of the taillight unit, wherein the rear fender has at least one portion provided inside the respective seat rails in a widthwise direction of the motorcycle, and the rear center lower cover is interposed between the rear fender and the left and right side body covers in the widthwise direction of the motorcycle, wherein the rear fender comprises a horizontal portion and a rear hung portion, wherein the rear hung portion has a width extending in the widthwise direction, and the rear center lower cover has a width extending in the widthwise direction, the width of the rear hung portion is smaller than the width of the rear center lower cover, wherein the rear center lower cover includes left and right bends (57L, 57R) provided at a bottom of the rear center lower cover, the left and right bends protruding inwardly in the widthwise direction, wherein the horizontal portion includes a projection protruding outwardly toward the rear center lower cover in the widthwise direction, and wherein the left and right bends protrude inwardly in the widthwise direction beyond opposite ends of the rear hung portion and are located above the opposite ends of the rear hung portion, and the projection protrudes outwardly in the widthwise direction beyond the lateral inner ends of the left and right bends and is located above the lateral inner ends of the left and right bends, whereby the projection, each of the bends, and the rear hung portion define a labyrinth structure. seat rails disposed above a rear wheel and supporting a seat; a taillight unit disposed on the seat rails for emitting light rearward; left and right side body covers (35L, 35R) disposed on the seat rails and covering lateral sides of a body of the motorcycle, the left and right side body covers covering the taillight with the taillight unit held between the left and right side body covers; a rear fender disposed on rear parts of the seat rails for preventing splash of muddy water as the muddy water is forced upwardly by the rear wheel; and a rear center lower cover covering a lower side of the taillight unit, wherein the rear fender has at least one portion provided inside the respective seat rails in a widthwise direction of the motorcycle, and the rear center lower cover is interposed between the rear fender and the left and right side body covers in the widthwise direction of the motorcycle, wherein the rear fender comprises a horizontal portion and a rear hung portion, wherein the rear hung portion has a width extending in the widthwise direction, and the rear center lower cover has a width extending in the widthwise direction, the width of the rear hung portion is smaller than the width of the rear center lower cover, wherein the rear center lower cover includes left and right bends (57L, 57R) provided at a bottom of the rear center lower cover, the left and right bends protruding inwardly in the widthwise direction, wherein the horizontal portion includes a projection protruding outwardly toward the rear center lower cover in the widthwise direction, and wherein the left and right bends protrude inwardly in the widthwise direction beyond opposite ends of the rear hung portion and are located above the opposite ends of the rear hung portion, and the projection protrudes outwardly in the widthwise direction beyond the lateral inner ends of the left and right bends and is located above the lateral inner ends of the left and right bends, whereby the projection, each of the bends, and the rear hung portion define a labyrinth structure.