Remember the Camaros with the "backward" facing cowl on the hood that had "Air Induction" decals on it? In high school I figured the chevy people were idiots for facing the cowl the wrong way. Later I learned that the region between the windsheild and the hood was at higher pressure than anywhere else on the front of the car.
Point being that the intuition of "scooping" air as it goes by in order to force it into the engine doesn't always pan out. Especially if you aren't ducting it directly into your airbox. I think the experiment we want is to monitor the pressure at the airbox inlet with and without and side cover mods, maybe also monitor engine temp to see if we are trading off engine life for performance. I don't expect anyone to actually run this experiment, but if they did I'd like to hear the results.
Rob