To seal between the end panels and the door frame,install a deep channel or pocket on the door frame that surrounds the edge of the end panel. Use a brush-type seal on the channel that seats against the inside surface of the door. Arrange the seal so that the panel does not contact the seal until the panel has entered the channel. To reduce the resistance of the seal, install it at a slight angle to the edge of the panel, from top to bottom. In this way, the panel pushes through only a portion of the seal at any point in its travel.