custom enclosure idea

I have a 2003 GMC Sierra Extended Cab. I am wanting to build a box that imitates the back seat - the box is meant to house 3 15" Elemental Design (Black cone with Blue E). I want the box to basically be the back seat ( this includes seat cushion and back support with head rest.) I built a box that housed these same 15's in an 92 extended cab S-10 - so i know i could completely lose my back seat to get them in. I am willing to only use 2 in the set up if it is necessary. Any input is greatly appreciated.

Three 15s will require a lot of space needed to vibrate that air. Any reference photos to show what you are working with?I have not failed. I've just found 10,000 ways that won't work.

When you do not know what you are doing and what you are doing is the best -- that is inspiration.

any progress on the install?  i did this a while back for a friend using 4 12s