A liquid container has a removable bottom lid and a drain opening formed in the center of the lid. The motor vehicle includes a B-pillar and a hinge pillar incorporating a hinge assembly. The intermediate air duct houses the air mover, which creates an air stream circulated through the duct work that blows an air curtain from the supply air duct to the return air duct. The roof, during oscillation of the chamber, remains fixed with regard to the base as well as in a closed position with regard to the chamber.