Sub for factory box
 

I want to keep my stereo as factory looking as possible in my 2011 LS. I simply want a little more bass so I found a GM parts dealer selling the factory sub box sans the amplifier. I plan on using the PAC AOEM-GM1416A to get some signal to the back and will purchase a modest amp to stick in the spare tire well. I know the sub enclosure is designed for an 8" speaker but would it that difficult to make it wide enough for a 10" or possibly even a 12" one? In looking at the enclosure a 12" sub might a stretch because of where the hole is in the box. For those that have the factory sub enclosure is it completely sealed? Anyone want to take a guess on how many cu/ft it is?..lol Anyone out there attempted what I'm planning on doing? I'll use the speaker grill from the sub obviously but just want to keep it looking as factory as possible. Thanks in advance.

i tried something like this to get a 10 to fit and there really much room to expand the hole the only option is out. ull have to make the hole in the beauty panel larger.