Looks like it was home made to me. I did something similar on my supra.
The easiest way is to make the box the way you want from cardboard. Get it exactly the right size then use the cardboard as stencils to cut the material. I bought a big peice of broken plexiglass for cheap and made a decent looking air box.
biggreen96: I think the silver one is different, I used photoshop to brighten up the areas of the two other pics and no hole exists on the passenger side of the intercooler for the black ones.