Awesome!! Nice design sure beats the hand pump water tank built into my AEV bumper. Only problem is I know those stock bumpers take a beating out on the trail. I have yet to see a stock bumper without some sort of damage when used on difficult trails. However everyone has their own purpose for their jeep so for some people this design would work fantastic.
No offense but whoever mentioned it as a gas tank, that's a really stupid idea. There is a reason regulations moved gas tanks to the side of the vehicle and you talking about putting it even further back and more exposed. That just seems like a time ticking disaster waiting to happen.