I have a 2006 Odyssey ex cloth. The van has 550 miles on it. The vibration has been there since mile #1. I just had the van serviced at Rick Case Honda in Ft. Lauderdale. While I was there, another woman that had a 2005 ex leather was there for the 6th time for vibration. One of my best friends has a 2006 exl-dvd and he has the same problem. This has nothing to do with wheel balancing. After rick case gave me back the vehicle it rode worse at low speeds and slightly better at high speeds. My buddy stayed with the shop manager for 4 hours today. They feel that the tires themselves are the problem. While going 50 mph and light gas the problem is real bad. I let off on the gas at this speed and the problem almost disappeared. This leads me to think that this is a transmission problem or axel problem. Anyone else out there feel this vibration (seat of your pants, not steering wheel) please post here!