I live in the Manchester and Tullahoma area and am offering rides back and forth in town (grocery runs, to and from hotels, etc.). Car fits myself and three others comfortably or 4 if you are super thin or don't mind squishing.
I can pick you up at whichever gate you request and take you to your errand and back for $20. One way is the same fare ($20), as it will still take me the same amount of time to get to your location.
Clean car, excellent A/C, friendly driver, knowledge of the area and pretty open availability.