Abstract: A retaining structure and fastener assembly for securing a resin panel to a vehicle body. The panel has an inner surface and a retaining structure extending outwardly from the inner surface. The retaining structure has a retaining wall with a slot for receiving a shoulder of a bolt therethrough, so that a head of the bolt is retained between the inner surface and a washer for securing the panel to the body of the vehicle. The slot is oversized relative to the shoulder of the bolt so as to define a predetermined gap therebetween to accommodate thermal expansion and contraction of the panel, thereby preventing building of the panel relative to the vehicle.