[gumby79]

You are in snow country as well. ? Have you noticed a significant reduction in the volume of snow accumulation on the tailgate? Just about every PU hear in Montana has the complete back (top of tailgate/campershell to bottom of bumper) covered with thick snow kicked up in the wake.
Every PU I passed was Wight out even the lights makes them hard to see, there head lights are a better indication of there presents than the covered tail lights.
On December 24 I drove 100mi in hevy snow @60-45mph and this is all the snow I accumulated, see pic. attached.
Notice the gap between the bed and bumper. This indicates to me air flow through the gap. And also the ball holes in the step. Have been kept open from air flow.