Ok so I searched for a posting about how to cut my back seat so the sound from the sub will come into the cab better and could not find a how-to.
Mind you, this only took about 15 minutes from start to finish and now my system hits much harder. Almost as hard as with the seats down. Only tools you need are a dremel tool and some desire. I am sure it will sound even better if there were nothing blocking the path like the cloth, but that also helps to not let on there is a system back there.
With out further ado...
First unzip both sides of the seat cover and lift up the back portion. Then lift enough area on the center console side to get at the plastic. Remove the hard cardboard in front of the future hole. It is put in between the seat cover and a black cloth behind the seat. Mine had 2 tabs holding it in that 'pocket'. The bottom tab of that cardboard was stapled to the plastic of the seat and the other is just a press fitting through a hole in the cloth. I also removed that black cloth since I really dont need it.
I used tape to draw out a box on the back of the seat and used the dremel with a drill bit attached to drill/cut out the back of the seat. When I finished I broke off that piece of plastic then moved to the front of the seat.
Cutting the front part of the seat is easy also as long as you pull back the seat cover. Fold down the other seat if you want just to be safe. I left the outer edge of the seat intact so the seat cover would have something to use for form. Do plan to vacumm out the car though.