The idea is to Park Stay Fly. We booked in for a 9:20 shuttle in the morning, a family of 4. At 9:20, as we arrived in the lobby with our luggage, I saw the shuttle pulling away.
No effort was made to check with us or to hold the shuttle -- which left early! -- and very little effort was made on the part of the front desk staff to assist us in getting the shuttle to stop or turn back for us. "Nothing we can do..." except call us a taxi, which cost $25. Still likely less than the cost of parking at DFW for 10 days, but very frustrating all the same.