A molding member for an automobile window plate includes an extruded elongate member with upper and side portions to continuously extend along upper and side edges of the window plate, respectively, and having a main section for covering a gap between the window plate and an adjacent automobile body panel, a lip section projecting from the main section to cover an outer periphery of the window plate, and a leg section extending from the main section into the gap for retaining the molding member in place. The lip section is provided with a first groove portion adjacent to the lip section and extending along the upper portion of the elongate member, and a second groove portion spaced from the lip section and extending along the side portion of the elongate member, to define between the lip section and the outer periphery of the window plate a weir solely along the side portion of the elongate member. The elongate member is adapted to be subjected to a permanent plastic deformation such that the first and second groove portions are aligned with each other substantially in a common plane to form a continuous single groove for receiving upper and side edges of the window plate.