Well I recently took all my interior out (everything still out except driver seat and dash) to deaden my interior. I am going to put two ten inch memphis shallows under my rear seat in my 99 ford f150 ext cab, but after seeing everyone building walls and the such I am wondering about the same. My it is so tempting. I am wondering about tryin to build a wall but I dunno what type of wall. I like vented enclosures, but I'm seeing people doing these 4th order enclosures and well my question is could a 4th order be done behind my front seats like a wall? I was planning using 4 or 6 15's. I want to be able to do 150's at least all day long on whatever music I wanna listen to. It is my daily but what kinda subs and what's should I look for?