A vehicle door assembly is provided that includes a retainer that secures to a door body panel, specifically, to the door inner panel, and is configured such that a door trim component or components may be secured to the retainer, rather than directly to the door trim panel. Door trim components of lightweight materials may be used, with the retainer providing the structural integrity required for securement to the door inner panel. Because it is not a visible component in the assembled door, the same retainer design may be used for doors of different models in a given vehicle platform, with different door trim components of different materials or styles consistent with the different models secured to identical retainers.