According to the
manual, pg. 417, "...towing behind a motorhome can damage the transmission."
Here's a thread on another website that claims Honda stopped allowing it after 2006 because people didn't follow their recommended procedure to prepare for towing:
Towing Honda With Automatic Transmission - Towing - FMCA Motorhome Forums
Here's another answer to the question:
http://www.justanswer.com/honda/7q53...dyssey-ex.html
Note: the 2012 Odyssey was also available as an AWD. They could only be towed 4 down or on a trailer, you can't tow with the front two wheels on a dolly.