This is a storage rack I had in my TJ. I made it a few years back out of 1/8" wall 1x steel and expanded sheet metal. It's pretty stout and mounts behind the seats. It has survived a healthy rollover and a flop or two in my rig. Only issues are a 3x4 hole cut in it to fill my fuel cell(does not cause any issues). Also you need some type of bars from b to c pillars on the cage to mount it. I can assist you with this if you buy the steel. If you were feeling real saucey you could make it into a bad ass receiver rack too. $65 obo Here are a few pics..
