A high retention force fastener for fixing at least two panels together is disclosed. The fastener includes two components. One component is a metal clip and the other is a plastic insert that can be substantially inserted into the metal clip. The metal clip includes a body having opposed panel engagement features extending therefrom, an insertion stop plate spaced apart from the engagement features and plastic insert locking tabs extending from the stop plate. The metal clip is preferably U-shaped and includes two sides joined by a connector. Each of the sides includes a pair of the panel engagement features. The plastic insert includes a head and a leg for insertion into the metal clip. The leg extends from the head. The plastic insert additionally includes metal tab engagement arms extending from and integrally formed with the head for engaging the plastic insert locking tabs of the metal clip.