Poor guy's Air Deflector:
Air would hug the roof and go down between the cab and shell, creating a horrible din.
As you can see, the air now flows over the gap.
You can see how the cab aerodynamics work against streamlining.
Two different size of hose held in place with 3M Painters Tape.
Rain hasn't bothered the tape used in this temporary experiment I did a year ago.
__________________