Road Runner Nest

HI all. I'm gathering the last parts for the body on the runner and one of those is a new full left side quarter from AMD. My question is what is the difference between the quarter panel with and without the "inner reinforcement"? My unit has been sectioned around the wheel well but no rust or damage to the rocker, wheel well, or trunk extensions. So what are these reinforcements to the qtr? I should mention, I see them in the AMD kit, but after looking in my car and pictures of cars with the quarters removed, I have no clue where they would go and what purpose they serve.

Thanks RC

Ok, Got word back form AMD. The reinforcements are part of the structure that, ( if your car had serious rust) are usually needed to do the replacement properly.