Abstract: A cross-piece (16) for dividing the window frame carried by a vehicle door (8) into a small part for receiving a fixed pane of window glass (54) and a large part for receiving a vertically slidable pane of window glass (56) defines two oppositely facing channels (52, 53). Channel (53) receives the slidable pane of window glass (56) and is formed by an extruded sealing profile (58). The extruded sealing profile (58) is mounted in rigid division bar (74) which extends between the channels (52,54). The assembled sealing profile (58) and division bar (74) are then placed in a mould with a fixed pane of window glass (54) during which the division pillar (92) is formed by a moulding operation. This moulding operation moulds the division pillar (92) to the fixed pane of window glass (54), the division bar (74), and also to the extruded sealing profile (58) at regions (98,100).