That is also an option you can do and I looked at, but NACA ducts really serves a different purpose.
That is trying to get air into your air box, I have my 2j intake with the filter in the cowl area.
With a turbo charger the ram air effect will do really nothing, the turbo is sucking in air faster than it can be shoved in by air speed, you just need to make sure it as a good place to pull it from.
These are no where near my intake, they are to draw heat out from under the hood and provide a good outlet for air to draw through from the front air damn of the car at speed. They may not be perfect placement or design to have the best effect that I am searching for, but without a bunch of testing its what I can do just taking a shot at it.