Due to a 'major itinerary change', we will also have two 12-hour layovers in Mexico City. Our plane will arrive at 6:47AM and our plane to Puerto Vallarta does not leave until 6:30PM (same deal on return flight). It will be a Sunday both times. I am very much interested in markets, street food, etc.
What would you suggest for a plan of action for exploring some good spots, leaving from and returning to the airport in good time for the next flight? There will be four of us. Logistically, it sounds like using a legitimate taxi hired from a booth in the airport is the way to go, correct? We've never been to Mexico so even the most novice of suggestions of not-to-miss things would be well received.
Thanks in advance.