The Rust Monster...

left, back, picture, forward, long, connects, firewall, centerline, guys, underneath, pinch, welds, extends, behind/above, underbody, panel, middle, rust, monster, rusted, side

See the bar in the middle of the picture? The one that extends back behind/above the underbody panel? What is this bar and where can I get more? Left and right side are both rusted all the way through. This picture is looking forward and left from the back end of the car. The bar is about 18