Perhaps this will help you out-
Haha, that picture makes it more confusing! I was certain it was G302 which the 03 manual says it exists but doesn't show you where. My manual shows it roughly the same way as those pages (minus the export options), which seems to imply it is STARTER MOTOR (B+) however(!) if you go forward a couple pages to figure 10 (Rear Engine Compartment) it shows STARTER MOTOR(B+) now coming from the tunnel! Later the manual also notes that the wire colors for the starter are red, which is the color of the wire in the tunnel.
If the wire labeled STARTER MOTOR(B+) Fig 1. Left Engine Compartment is actually a negative lead/ground for the starter then that makes sense and I might be able to find it's location since I'm assuming they wouldn't put a red wire and a black wire on the same starter post, no?
Edit: apparently they did...
Mystery is solved