What is this strap/bar on Aussie K-member?

Thanks for the compliment! First off - it is a clone. And I'm good with that. I did the whole nut and bolt restoration on a 68 Road Runner and told myself that was the last time for that. When time came for another project I wanted something that I could modify as I liked and not have to worry about originality. The Charger is a 73 VJ that came with the small 215cid six and a 3 speed, original color was the Super Blue (close to our B5). Somewhere along the way it got a ford rear end from a Ute that gave it disc brakes in the back and repainted white. The motor was swapped to a 318 and 4 speed and a VH grille and other VH items, then painted orange. It was shipped to the States and then sold to a guy in Seattle area. I believe he installed the 340 and 6 pack. I added a few more items like new carpet, hood pins and left hand pistol grip and some 383 torsion bars. Having a lot of fun with the car.