A reusable press-in retainer assembly for joining a first component to a second component, said retainer assembly comprising: a clip element including a proximal head and a distal base of arrowhead configuration projecting outwardly away from the proximal head, wherein the distal base includes a pair of flexible wings extending in angled relation away from a distal segment of a central stem, the central stem being operatively connected to the proximal head, a collar defining a platform positioned in spaced relation above the proximal head and in spaced relation below lower edges of the flexible wings, a connective structure disposed between the proximal head and the collar adapted to fit in sliding relation within a keyway slot in the first component; characterized by a sleeve adapted to matedly receive the distal base, the sleeve including a nipple adapted for insertion through an acceptance opening in the second component, the nipple projecting outwardly away from a radial base, the nipple including an interior axial passageway and a pair of opposing elongated window openings adapted to pass the wings of the clip element to a position outboard from the nipple upon insertion of the distal base into the nipple to a first degree of insertion, the window openings having an effective height such that the wings are compressed radially inwardly towards the central stem upon insertion of the distal base into the nipple to a second degree of insertion deeper than the first degree, wherein insertion of the distal base into the nipple to the second degree of insertion is blocked when the first component is in place between the proximal head and the collar. a clip element including a proximal head and a distal base of arrowhead configuration projecting outwardly away from the proximal head, wherein the distal base includes a pair of flexible wings extending in angled relation away from a distal segment of a central stem, the central stem being operatively connected to the proximal head, a collar defining a platform positioned in spaced relation above the proximal head and in spaced relation below lower edges of the flexible wings, a connective structure disposed between the proximal head and the collar adapted to fit in sliding relation within a keyway slot in the first component; characterized by a sleeve adapted to matedly receive the distal base, the sleeve including a nipple adapted for insertion through an acceptance opening in the second component, the nipple projecting outwardly away from a radial base, the nipple including an interior axial passageway and a pair of opposing elongated window openings adapted to pass the wings of the clip element to a position outboard from the nipple upon insertion of the distal base into the nipple to a first degree of insertion, the window openings having an effective height such that the wings are compressed radially inwardly towards the central stem upon insertion of the distal base into the nipple to a second degree of insertion deeper than the first degree, wherein insertion of the distal base into the nipple to the second degree of insertion is blocked when the first component is in place between the proximal head and the collar.