Hi All, I just booked thru this outfit: www.GlobalAirportParking.com. Have used them in Greensboro with no issues. It's about $45 for the time period I listed. You tell them what time you arrive to park and what time you'll pick up your vehicle, then they calculate the cost. They have free shuttle 24/7 to the port and airport. If you go to the website, select your port, or city, or airport and the system will find several options for you to select from.
Hope this reply goes thru!