The invention relates in particular to a separable fastener system for fixing together an element, e.g. a vehicle window, and at least one other member, such as a brake light. The system includes an intermediate structure such as a gasket made of elastically deformable material; intermediate fixing means; a positioning surface; and a stud with an expansion space around the stud, and an orifice associated with a housing for holding captive a shank without injuring the orifice.