I didn't fancy spending money on an induction kit just for induction noise as I have read that you don't get any extra power from a better breathing filter on the Z.
So.......I took out the filter box and attacked it with a 24mm hole saw , a couple of holes in the sides, 5 on the bottom and a couple on the front, none on the top. Put it back in with a new standard filter element and it looks the same.
The noise however is great, cost nothing and it looks nice and standard You never know, an insurance inspector might want to see if there are any engine mods someday if the worst happens.
After have loads of Honda CRX's and a couple of Type R's in my youth (10 years ago!) I never saw anything wrong with this.