I looked at the whole washer bottle issue when I had my stock air intake out and I just don't see how it is that big of a deterrent. Air is hitting the car in the front, the 1LE splitter covers most of the bottom to the wheel well. Maybe on non splitter cars the air is more accessable from the bottom, but the air would have to travel backwards and up to get any effect. If you look at the FEA flow data of the Z28 and how the air flows thru the grill and out the hood, but it flows towards the headlights. I think if you mod the plastic part behind the grill directing air at the radiator that this would increase the ram effect. The quickest path is around the back of the headlight to the grill. In mustangs the Drag trick was to pull the headlight at the track.
When I take the bumper cover off this weekend to do the grille, I am going to see if I can design a ram-air scoop or redirect from the grill to the air intake.
Note the air behind the Z28 badge, if the plastic directing was opened up a little I could see it increase. The above pic showing the air movement out of the hood, is the reason I removed the rain deflector. Lower hood pressure means faster times.
Look at the air hitting the headlight area and towards the center, there is alot of resistance that could flow to the filter