So I proved that Gold Rush is not impossible yesterday; just almost impossible. There must have been some stars aligning or something because I ended up in the Lost City with a teammate that was really good, another that wasn't great but he stuck with me while I was carrying the treasure, and I found the routes that enemies almost completely avoid. You can cross most of the level underground and you won't see anyone, then use the stairs on each side of the level to get up to the higher parts since they never seem to go to the stairs either.

We were working so well together that when I turned a corner and saw a guy with the Gau-19 standing in front of me and ran back behind the wall like a coward they popped around the corner and killed him in about 15 seconds and we were moving again. I doubt I'll ever see team work like that again without getting a party from my friends list together.