i used to have a POD on the wagon, first it was in the airbox, i removed the snorkel and just left the hole, throttle felt more responsive:
then i took the airbox off and just left it in the engine bay, throttle felt the same, air induction noise was much louder.
i then decided to move it behind the front bar down the bottom and cut out the plastic bit where the foglights go on the exec front bar so that it would suck plenty of air, throttle felt a tad better and the pod was DANG LOUD! the car was nicknamed the 'aeroplane':
Eventually took it off, as it was just loud and gains was nothing to get excited over, i figured that with the pod being down behind the bumper, the air has to travel too far and threw 2-3 bends so it wouldnt be as efficient. if the pipe was straight i'm guessing it would've been much better.
atm im running the bottom half of the monaro cai with the 2 hole mod, and a peice of pipe going from the big hole straight into the back of the headlight to direct the air in.. seems to work the best out of all the ways i have tried and its not extremely noisey!
good luck, an-D