Hmm, but surley, the air will go through the grill, and slam into tha back of the engine bay/radiator/engine/everything else unsmooth in there, and cause a certain amount of drag, wheras (theoretically) it should hit the tape and flow around. I guess, the tape was a pretty blunt surface, so might have had a pretty adverce effect. I have no idea really, just a basic kinda thought. Its pretty impossible to tell from just looking really..