My buddy has a 1996 Sport and we were looking at his airbox for this same reason. The 96 has a conical filter and gets its air from a hole in the fenderwell as opposed to my X breathing from the space behind the passenger headlight. I don't even have a hole in the fender.
The fender area seems to be the most popular place for cooler air so if I had that option I would go for that. In looking at my friend's 96, there was a baffle inside the fender that you might want to remove. We didn't get as far as actually looking that part over, but I would guess it was some kind of silencer and if you don't mind a slight intake noise under load, it is better out than in.
Another thing you can do is modify the air box so it has more free area at the open end. When I looked at it, the box itself didn't look too restrictive compared to the size of the MAF, though.
In a prior life I had a V6 Contour that I modified with an airbox from the SVT Contour which looked a lot like the box on your truck. The K&N filter for that box was too long and seemed to almost close off the intake hole so I cut about 1 1/2" off the flter with tin snips and took the plastic nose cone from the top of a stock paper filter and glued that to the K&N with "GOOP". Flow was greatly improved as was gas mileage. The filter never failed and I am sure I improved flow in a big way. I am sure you can do something like this to your X as well. Take a look at the stock Contour SVT filter and you will see the nose cone. When installed, the filter box looked like a jet engine.
I would bet when baffles are removed and a filter is optimized to the air box you will find that there is not too much restriction in the stock air box. Cutting it up will only allow warmed air into the engine which will have the opposite effect to what you are looking for.
