Used door lock and trunk lock cylinder retainer clip. Not exactly the same as the door lock clips. Trunk clips have the small hole, a hooked tool would be used for removal. Not used on 1967 - 1968 Cougar trunk lock cylinders.
*Note - For use on Cougar trunk locks built prior to 3-1-1972. Please see Ford part number D2WY-6243629-A for your Cougar needs on cars built after 3-1-1972 (used only).