Which way to place inverted subs?

[Stephen Dunnington]

So the other day I reversed my subs so I can get more cubic room in my box, My trunk is pretty small and my ported 2 12"s take up most of the space, with about a foot and a half of space on each sides and 2 feet from the sub to the back of my trunk. Should I have my subs facing my back seat and up against them? or up against my bumper and move it to the left(port is on the right when facing trunk)