Temporary closure device for an opening element on a fixed chassis part of a motor vehicle, said opening element comprising a housing for receiving a lock and said fixed part comprising at least one tapped hole for fixing a strike, the device comprising a plastic body which is equipped with means for mounting same in said tapped hole and comprising, at a first end, a limit stop element which is intended to cooperate with a first rim of the housing as the opening element is being closed, and a second end comprising a means for retaining said opening element in the closed position against the fixed element, and intended to penetrate the housing behind a second rim thereof, the retaining means being formed by a resilient tongue which can bend under stress from the second rim when the opening element is moved from the free position to the closed position thereof, characterized in that the area of the body that essentially corresponds to the base of the tongue extends into a plate which is suspended above a recessed area, the plate and the tongue being connected by means of an arch forming a flexible connection.