A rear window assembly includes a glass flange positioned in a window opening. The glass flange includes a body mounting flange mounted to a body of a vehicle. The glass flange has a first mounting pad defining a first mounting area for a window for mounting a first glass variation to the vehicle. The glass flange has a second mounting pad defining a second mounting area for a window for mounting a second glass variation to the vehicle. The second mounting pad is recessed toward an interior of the vehicle. The second glass variation has a slider rail and a slider glass, while the first glass variation is devoid of a slider rail and slider glass. The glass flange selectively receives either the first glass variation or the second glass variation in the window opening.