Abstract: A dropglass window module having a sliding pane between a first fixed pane and a second fixed pane, and a skeletal framework comprising left and right division bars, a header and a beltline support where the header and beltline support are each connected to the division bars. The skeletal framework and the fixed panes are bonded together by a plastic encapsulation frame which is preferably injection molded. The fixed panes are positioned entirely within the circumference of the frame. The division bars cooperate with top and bottom segments of the frame to define a central opening, and the sliding pane is movable by a motor between a full open position and a closed position where the sliding pane closes the central opening. In at least some preferred embodiments the beltline support is entirely encapsulated by the plastic frame.