A frame assembly that includes a first frame member, a seal, a second frame member, and a coupling mechanism. The first frame member includes a first extension and a second extension. The seal extends between a surface of the first extension and a surface of the second extension. The second frame member includes a third extension. The coupling mechanism is adapted to connect together the first frame member and the second frame member. After the first frame member and the second frame member are connected together, the first extension, the second extension, and the third extension cooperate to form a channel. The channel is adapted to receive a tonneau cover enclosure panel.