It's happened to me as well. Twice. Same scenario - hot day, stop and go traffic, no air flow past the car, no indications of anything over temp - oil, water temps all normal. After about 30 minutes of this, the engine starts to idle rough, then a few seconds later dies. Can't restart. Car will crank and crank, but no fire. After about 5 minutes, the engine will start, but idles rough. Needed to keep my foot into the gas to rev the engine to 2000 - 3000 RPM to keep it running. Once traffic cleared and I got rolling again all was fine. Mine's an 06.