I also saw several RVs and other homebuilts in GAC. Didn't try to approach them and ask why they decided to park there. Maybe next year I'll ask.
The problem is Rick those areas are always reserved either for groups (the Spartans, Ercoupes, Swifts, etc.) or are already paid up spots like I've had done for me in Camp Scholler. You'll need to be there by Tuesday or Wednesday before the show to try and claim one of those nice spots.
My first trip to Oshkosh was in 1987, I believe the red shower in the N40 was nearly new then as GAC was pushed west by the expansion of warbirds. IIRC the shower house in warbirds was just east of the beginning of GAC back then. The "taj mah shower" is excellent. They just need a couple of those down on the south end, along with a camp store!