Hey Hoosierdaddy, I've actually did the single fin box idea after some trial and error before I came up with same thought on the exhaust fan on the back of my case, and it works great. Very little restriction, and you would have to be in pitch black darkness to see any light and only after your eyes adjust to the dark. Other wise no light comes out and is 99% effective. But I like your z fin idea also, as well as Scrubninja's design to.