We had the Honda Trifold Tonneau installed on our -T by the dealer. Have not put a lot of miles on yet (< 3 days). But yesterday we drove almost 300 miles in rain almost all on freeways. It varied from a heavy downpour to just a nuisance. When I got home, I checked inside the bed. Not a drop of water could be seen. Obviously that was a early experience, and may change, but for now I am very pleased.