This invention relates to a fastener, which expands by the insertion of an expanding member, preferably a screw. The fastener comprises a substantially flat head and two expandable legs. The head has an upper side and a lower side, preferably separated by a gap. The head also has a hole (round, oblong or otherwise shaped) in which the expanding body may engage or pass through for expanding the legs and securing one object to another object, such as a plastic panel to a metal sheet. The fastener also comprises a Y-shaped funnel configuration, which has been formed by a partial cut of the legs. Miscellaneous configurations of the Y shaped legs provide improved guidance to the expanding member, improved engagement to at least one of the objects, such as the metal sheet for example, and improved engagement to the expanding member, among other advantages. The fastener may also comprise portions under the upper side of the head, which portions are engageable to the expanding member. Further, the fastener of the present invention may comprise an elastic body at least under the head. This invention also relates to vehicles comprising parts connected by the fasteners of this invention.