An airbag module assembly including a module housing, a door and a door retainer ring. The module housing forms a compartment adapted to contain an inflatable restraint airbag cushion in a stored state. The module housing has at least one open end, and includes at least one side wall and at least one face wall generally perpendicularly disposed relative to the at least one side wall about the at least one open end. The door retainer ring is adapted to be joined to the module housing about the module housing open end. The door includes a circumference portion and has an inner surface and an outer surface. The door, in a static state, is disposed over the module housing to enclose the module housing open end with at least the circumference portion of the door disposed between the door retainer ring and the module housing. The circumference portion of the door includes at least one release portion and at least one hinge section. In the assembly, upon inflation of the inflatable restraint airbag cushion, the inflatable restraint airbag cushion expands against the inner surface of the door, whereby at least the release portion is displaced from between the door retaining ring and the module housing with the door rotatably hinging about the at least one hinge section.