I just assumed the the rubber deflector on top of the plow was standard with the Fisher as it is with the Western. What is the purpose of these rubber deflectors? I would guess it would keep snow from coming up over the plow? Are these only needed if you are plowing at high speeds. The dealer wants $155.00 for them. I know that's peanuts in the big picture after buying a plow and spreader, I was just wondering if it's worth it or not?