I've got two small (but powerful) Jl amps,installed in the glove box behind passenger seat..
Mind you, if you remove the OEM sub, you could re-use the space and stuff the amps in there and still retain full use of the glove box
That will be my plan also. As my glove box was removed to house the NOS bottles, but now they have gone I have a cavern of space and I can get two full size detailing bags in there. So extra storage space