Honda Pilot fiberglass sub box

I have read some threads on another forum where people have modified the factory sub enclosure (the right side panel in back) to fit an aftermarket sub in its place. This one is where they just ran a sub in free air but used risers made out of wood to allow for the woofer to fit depthwise: https://www.honda-pilot.org/forums/showthread.php?s=ffb233a0cc937c074507cf2bf814d7db&threadid=4437&perpage=15&pagenumber=2 And here is one where they cut the sheet metal then fiberglassed part of the inside of the panel and fiberglassed the panel they cut back on. https://www.honda-pilot.org/forums/showthread.php?s=ffb233a0cc937c074507cf2bf814d7db&threadid=4437&perpage=15&pagenumber=2 (I would never do that...)

My question is would it be possilbe to make a glass enclosure without cutting the panel. Or should I maybe just stick with a sub in free-air. It would be mainly an SQ system for my dad but he probobly would crank it up every once and a while.

Could I maybe fiberglass over the top of part of the metal panel, mount MDF risers on the perimeter of the fiberglass, place a mdf ring for the sub (raised up by dowls) above the factory subwoofer hole, and stretch fleece over the whole thing and glass it? I could glass the inside part of the sheet metal that is accessible through the hole to finish off the enclosure. Kind of like this picture https://img.photobucket.com/albums/v521/customsuburb/pilotsubFG.gif (sorry about the crappyness of it) where the red is fiberglass and the brown lines on the perimeter of it are the MDF risers. I'll try to explain it better later.

Yeah, that first install is pretty ghetto lol. Maybe I'll just put a regular box in their or a fiberglass box somewhere else in it...

I accidentally put the same link twice on my first post. Here is the $4000 system install in a pilot that an installer did... https://www.honda-pilot.org/forums/showthread.php?s=a20be5d866a1a9a15ab1c458acee07d9&threadid=10630&perpage=15&highlight=fiberglass&pagenumber=1

Now that is some serious cutting. lol

I could never cut that much sheet metal out of a vehicle....