Abstract: A vehicle and luggage box assembly (40) includes a vehicle (42) and a luggage box (44). The luggage box (44) includes an open-ended chamber (61) with a flange (62) that extends perimetrically around an open end (49). A perimetrical chamber (66) is molded inside the flange (62). A perimetrical groove (68) is cut through the flange (62) and into the perimetrical chamber (66), thereby forming a perimetrical T-slot (70). A resilient gasket (72) is inserted perimetrically into the perimetrical T-slot (70), and a door (48) of the vehicle (42) closes against the resilient gasket (72). The molding process forms two separate chambers (66 and 94) in a single mold (100) by constructing a throat opening (122) with a dimension (120) that results in bridging across the throat opening (122), and that thereby results in the perimetrical chamber (66) being isolated from the closed chamber (94). Subsequently, removal of a web (92) transforms the closed chamber (94) into the open-ended chamber (61).