sub box question

i want to make a custom sub box that holds 2 10" subwoofers behind my car seats. I have a honda del sol, so i removed the back interior piece. So my question is how do i start making this box. Should i make a frame out of wood and wrap it with fiberglass to make a box for each sub and then connect all of it with fiber glass to make it look like one, or try to make one whole box for both of them?

http://www.automotiveforums.com/vbulletin/t53987.html if the link doesn't take you to the post then look in the del sol board. 2 10" polks they sound great