I believe not much is there. I have not taken that area apart yet in either of my x-fires but there are sub ports behind each seat. So, I believe all it is is 1. A separator between the front and the cargo area 2. A support structure to stiffen the chassis and 3. An area to house the sub and or amp? Thats what I can come up with without taking it apart. Not to mention a place to put nifty bag hooks and some accessory holders Any one please correct me if my logic is wrong.