After much searching, I have finally found the Ford part number for the trailer tow module under the driver's side rear passenger seat. This module completes the trailer tow prep package installed in our cars come from the factory. The module should be plug and play with no programming.
The part number is GN1Z-19H332-A. You can go to the Ford Parts website and see photos of the module.
To complete the wiring from the plug located under the left rear corner of the rear bumper, you will need this harness, part number - GN1Z-13A576-A. It plugs into the car wiring harness but does not have the trailer connector. You will need to graft on a flat 4 wire plug to this harness. Wal Mart sells the Hopkins Towing Solutions 4 Flat Extension 18 Inch Wire, 48185 for $4.95 (lots cheaper than your local auto parts store).