We have a 2010 Prius V with 100K miles on it. At about 90 K miles a soft hum started which now is quite loud. It seems to come from the rear wheels. I jacked the rear up and cannot determine that is the problem. To me it seems like it would be the CVT but jacking that front end up I could not determine a problem there either nor with the CVT joints or knucles. The Toyota Garage checked out and first stated they couldn't find the problem but suspect the rear wheel bearings. Another Toyota Tech took it out and states both rear wheel bearings are bad. So I have it scheduled but question that both go bad at the same time. In looking at the chats on the internet I doubt the rear wheel bearings are the problem. Any one able to help me?