System comprising a slide track for motor vehicle seat and a support. The slide track comprises a fixed rail and a movable rail which has an inner surface, an outer surface, and a through-window. The support comprises a body having a contact surface attached to the outer surface of the movable rail, and a tongue extending from the body to pass through the window of the movable rail and be attached to the inner surface of the movable rail. The tongue has a maximum extension into the hollow interior space E that is less than or equal to a thickness of the tongue.