........Autobody and frame repair, 44 years experience.nowgittineverything said:Looks like a moulding retainer clip for automotive or truck exterior trim. It snaps into the back of a moulding, then is pushed through a hole in the body, then an acorn or push nut is used to capture the stud, thus holding said item to the body of the vehicle........Autobody and frame repair, 44 years experience.