If Ford doesn't recommend it for towing 4 down, you'd do it at your own risk. Also, if it's not recommended, is a base plate even available? There were many issues with towing Ford automatic transmissions over the last couple of years, use the search box at the top of the page to read of the experiences of others with Ford automatics.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI