Power Window Motor Cable Retainer

I am working on the rear quarter window of my 66 Chrysler 300 Convertible and discovered that the power window power cable is just flopping around loose and getting caught in the window roller mechanism. The cable has one of those split bullet type plastic retainers molded onto the cable (see attached pictures) but I don't seem to seem a location where that retainer would plug into. Would anyone know where this retainer would go?
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Author: motorama55