if you dont plane on having the seat work as designed then just build a sub box and screw it to the floor then just mount the seat permanently on top of the box !

 

well i asked this question before and never got an answer. The way i looked at it i couldnt put a sub behind my back seat or anything like that so what i did was build a custom box that goes were the console goes. It fits a 10 and all i need to do now is place an amp and figure out how to wrap it so it dosnt look totally out of place. Ill try to get some pics up soon

 

on your sub woofer issue in your older Ford,,,,yeah there's no room under that backseat. You technically have three options but all three will require work on your behalf other than just throwing in a box and hookup up the wires. The first and easiest option is to consider building a small single woofer enclosure in the armrest glove box area when the armrest is down you will not see it and it is out-of-the-way. The second is removing the backseat building a flat subwoofer box enclosure all they cross the back basically rebuilding the back bench and then wrap Styrofoam and fabric over the top from the old seat that's eliminate need that big bulky thing that's back there right now. Lastly but A little bit more labor-intensive is attaching a shallow box on an angle to the back top corner of the ceiling but that's something you'll have to take interior measurements of if you do carry rear passengers