Here is a list of ideas (mostly loony)
Who are the racers seen on top of Elephant Butte?
Does the shot of Linzen at Lake Powell dock match the one where they went by mistake at the end of the last leg?
Map with Ford's Point, Elephant Butte.
Google route maps: Page to Ford's point, Ford's Point to Gemini Bridge, Gemini Bridge to Green River State Park, Greene River State Park to Bart's place, Bart's
Do we have instances of teams at the same place in the same shot?
I haven't looked carefully but are there any promo shots at Gemini that have shadows (on first checking I was not finding any)