I happened across this thread tonight - I had no idea you were building a full frame racer as well. We are moving in slightly different paths - you are going toward full race and I am moving back toward some race, some street. I had a new 10 GS Vette for a bit and had to sell it because every rock chip drove me batsh!t crazy so I learned I like 'em a little ugly and fast, not shiny and fast, as well.
I love the DTM stuff as well and thought about doing something like that with the Nova - when I found myself needing to narrow the front track to get the 12" tires in there I thought about pulling the whole fender out and just adding a 2" step at the rear of the front fender, similar to your rendering. Going that route with a Camaro should be pretty wild looking. I would stick with a rough look as you suggest you might for awhile - I don't plan to paint the Nova until I have a fair amount of track time on it and have done some sorting, because part of sorting tends to be a few off-track excursions that are hell on paint and low altitude front splitters. I have mowed a fair amount of lawn with my 914's splitter and my fiberglass nose has some damage to prove it
As for that thrift store, holy hats Batman! I have never seen so many hats in one place in my life, let alone calipers. Those AP brakes are certainly nice.
Subscribed - between your thread and a few that others that are posting here have going, I should get plenty of ideas for changes as my car progresses.