I wouldn't call it "hacking," just removing the bottom and affixing the filter to the top.
I have this right now and I'm not sure if it makes any power. I will be dynoing this at the ******* Rally dyno day and autocross next weekend so I will let everyone know if it makes any difference over stock.
I don't even care if it makes no power at all. The SOUND is worth the time to do it a million times over. Do it. You'll LOVE the sound.
LOL, well i tried it once. just taking the bottom of cause i have a classic with the AIV thing. But by fliping the top of the box over i think its better. it didnt do much for me, automatic so didnt notice any better throtle response, and didnt feel faster, but damn she growls. Dont know if its totaly worth it will find out next weekend, but if you are bored like I was go ahead and do it.
I like the way Jay H. (i think it was him) did it in his 200sx. Get another box and carve it up a bit and make a ring to hold the K&N filter on, and making the bottom part into a stand to hold the whole thing up, well he had his pointing back toward the strut tower, that might make a difference cooler air possibly back there away from teh radiator and exhaust manifold. I think his site is in his profile on the board here or he put it in a post somewhere.