Yes, another post about rust. I know, it's getting old, but I just want to showcase these areas since they are soooooooo typical on the e21. In the future we can glance over these sorts of repairs, but for now, let's grab our grinder and dig in once again.
Figuring out how to make bends that mimic stock metal can be a tricky thing, at times. You might find yourself digging around the shop looking for anything that can serve as a dolly to bang on. You get to be creative. No two jobs will be the same. Similar perhaps, but not the same.
I found myself on this day using the vice, my trusty hammer, and an old shot of weld wire to put a small kink in to match the body like of the rear passenger side valance. While it isn't 100%, it sure gives a pretty convincing profile that makes finish work a lot faster, and saves us from abusing fiberglass or bondo, like some clowns out there. (You ever see that guy who fixes cars using ramen and super glue? Yeah.... clowns.)
Also, the gas filler neck panel has been hole sawed out for the neck, don't worry. I didn't forget. Just forgot to snap a pic.