here's a goofy idea. mount a 7" radiator cooling fan in the wheel well compartment, pointing up at the 4" intake hole for the air intake. The fan works on 12v. If there's no real friendly way to bring outside air (to ram) then create your own. Have it switch operated inside under the dash and turn it on/off just to see if it makes a difference.
I say ya never know until ya try. Have you ever watched the videos on youtube were they run cars and trucks on a dyno and then run them with an electric leaf blower on the intake? Interesting to see at least. A lot of good things come from people just messing around.
So technically this would be cold air and not ram air. This is Ram Air X-51 hypersonic scramjet test: Flameout at Mach 5? ? The Register. Hypersonic air being forced in at Mach 4 to Mach 6. I had a similar question posted that my wife asked, it was along the lines of "why not run an air conditioning vent into the air intake of the car?". While the answer was that you cant get 1 for 1 power gain (since the car engine is producing the AC), I still didnt understand because the power is already being wasted since my car already has AC, just run a tube from it to your intake! Anyways..yeah fun stuff.
The one I happened to look at was rated for 1550 cfm. That's a fair amount of air. I believe much more than what's hitting the face of the filter (I happen to have a K&N panel filter). Probably resulting in a air daming effect.