[5.0 Junkie]

Interesting. They don't make toppers tall enough to go over the top of the trailer. That was why I was thinking of one of the adjustable deflectors at the back of it. I think the topper is going to help the most as it will greatly reduce the air hitting an estimated, 4'x8.5' area that is exposed from the top of the tonneau cover on the truck to the top of the trailer.

My wheels are already tucked in the wheel wells, ie, the fenders only stick out about 2" from the side of the trailer. I was thinking about just putting a skirt across them and putting moon caps on.