how thick does it have to be and when it is mounted in the box does it go flush in the hole you cut or do you just glue it in so it is under the surface of the xbox? i can't tell from all the pics i've seen. if i did want to do it flush, how would i go about do that? cutting it a little larger, sanding the outsides down around the opening and then gluing in???

1) it's hard as crap to get it flush, I had to for my dreamcast window (rounded one too) and it was a long ass time, but finished product it amazing, ill post pics when the led's are in

2) If you go to Lowe's , you can pick up a small sheet for about 4 bucks that's big enough

3) Most people have it glued below the cutout, so it's recessed