I have asked this question to a dealer and primarily the problem is the tailgate on the titan. The top of the gate as it's closed bumps out where the handle is. On a topper designed for the titan the topper rear hatch has a piece under the window that matches our tailgate's unique shape. On a topper for another brand truck, If it's a center mounted latch on the topper there is no clearance for the mechanism to turn. If the topper is the two latches with one on each side it may work but will still have a major leak issue where the tailgate sticks out beyond the topper. Hope this makes sense.