ok.. i've started the project..
yes there is plenty enough cable.
the amp is 9x9 but on one both sides its feet stick out adding a extra 1/2" in total. and the other way it needs access for the connections at both ends.
i have the passenger side design pretty much sewn up... i'm using one huge 16" x 16" panel to cover that side. behind it there are two umm cojoined? lol. boxes which give the
volume needed for one speaker.
what this means is. i have a small back section that plugs into the car, and a front section that covers all the stuff behind.
the beauty of this is there are no angles edges to cut on the mdf for joins, its all right angles.. perfect

i've decided i'm probably going to mount the amp to this big panel too. it makes more sense as the power connection etc would be closer to where it comes out from under the seats.
the sub will sit up in the upper left and will be protected by a 'ring' of mdf which i'll then put chicken wire over, i will then carpet over the entire thing.
the amp will then sit as high up on the box towards the other end as possible.
because there is a lot of 'non box' space behind the 16x16 panel i can bring a lot of the cables through to the amp on the outside tidily.
however. it wont be stealthed like i had hoped.
the other side is a BlTCH... there isnt much space...
i think i may have to build this other box with either many angles (even more added up cu in of space...) or... go the fiberglass route... which i'm not too sure of..
i'm probably gonna get the one side done.. try it out.. and then make my mind up.
i'm also gonna round off the corners of the 16x16 panel to make it look nice.. and will probably use big fat strips of velcro to attach it to the car properly...
i wont be putting box carpet on till i'm totally done with the box though. will prob use it without for a week or two to ensure no probs..