I've heard of people doing this by making up a box it if helps at all, and running a cold air induction feed from the surrounding box to the front bumper.
I think it might be a bit hard to fit a pod inside the stock airbox, although depending on which pod you use, one might fit inside.
I understand this is done to avoid problems with the cops, and also stop the pod from sucking in hot air from the engine.
Not sure how effective this actually is tho.
Would check if my apexi fits inside, but haven't got my car atm, being rebuilt.
Personally, i would think that having a pod inside a box would restrict the ammount of suction it could get.
Johno