I dunno... that looks kind of like a mess to me. Almost as if bad stuff was happening and they did what was needed to band-aid it. If starting from scratch and the rules allowed that would have been all tubing. What car is that though? I had to turn it upside down to see it better.
Little different situation with that car because it looks like the factory firewall and stamped floor are gone. They still have the OE control arms though... with a Lenco...
Are you planning to put a mid plate in? That will stiffen the firewall area and will mostly eliminate torsional twist but won't necessarily tie the overhanging outside panels to the inner structures like the bulkhead does. Perhaps a mid plate would make that bulkhead less important since there would be less force acting on that area?
Again, I know just enough to be dangerous....
