I have not had carb ice in my 150 other than "possibly" 2 times in almost 8 years of ownership
Both those times conditions were OPTIMUM for carb ice formation. I dont think that the airflow around the cylinders is affected at all. That air overpowers the small surface area of the filter opening sans baffling easily I would think. Might be some stuff going on turbulence wise at the gear opening, but I doubt it has other than a very minor effect on the flow.
