Honda sanctioned four-down towing on the Odyssey through 2004, then changed that stance starting with the 2005 models (and there is evidence that they did change transmissions that year). Some folks say the towing policy change was initiated by lawyers as typical corporate CYA; others say it was initiated by engineers, because there really is a possibility that RV towing will cause transmission damage, even if the proper Honda towing procedure (still dictated for "emergency towing") is followed.
Remco is no help -- their website says all Odyssey's through 2008 can be towed as-is, but on the phone they say their official policy is that the post-2004 versions are not towable.
Regardless of the official policy from Honda, some people are towing them anyway, so I'm trying to get a real-world progress report. If you've had experience towing a post-'04 Honda Odyssey four down, I'd appreciate the benefit of your experience. Have there been any transmission problems?
Thanks!
Denny