Abstract: A beverage container having elongated side walls is provided. The container side walls are preferably generally cylindrical and having an upper end and a lower end. The container also having a base portion that is connected to the side walls at the lower end of the side walls. The container further includes a stabilizing arm that has a first end and a second end. The stabilizing arm is movably connected to the base portion so as to be movable with relation thereto. The stabilizing arm may thus be moved from a position in which the stabilizing arm first end is proximate to the base portion and lies in substantially the same plane as the base portion to a position in which the stabilizing arm first end is extended away from the base portion and lies in substantially the same plane as the base portion. The first end of the stabilizing arm, when extended away from the base portion, may be inserted within the crease between the seating portion and the back support portion of a vehicle seat.