Looks great so far.
Hopefully you dont have to remove the subs at any point since you have them mounted from the inside of the sealed section. Unless you have something else figure out for that already.
Looks like its double layered everywhere except the bottom is single layer? I thought about that for my next build only going 1 layer thick on the bottom and double layered everywhere else for my cpillar 4th I have planned. Not sure if its really needed to go double layer since the floor kind of braces that side with the weight of everything against the floor of the vehicle.