Not that I'm a rules nerd, but what you did isn't legal either.
To the OP, per the rules you're supposed to use a sheet of metal the same gauge as the surrounding roof. The cleanest ways I have seen is people make a cardboard template of the hole and trace that to a piece of sheet metal and then trace another that follows the original but enlarged by say 3/4" to an 1" all the way around. They cut that, you could use tin snips, and the extra is that you have is cut into tabs so to speak and bent at a 90" angle. So, you now hae a piece of metal that will just fit right in and then just bend those tabs back and use them as places to rivet/sheet metal screw to something secure around it.
http://honda-tech.com/zerothread?id=530379&page=2
see the post about half way down by keithv to see what I'm talking about.
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