I know this thread is rather old, but the descriptions of the problems other people have noted match my problem rather precisely. Noticed it today for the very first time (it is my wife's car so I don't drive it all that much as we usually take my car for longer distance trips -- highway speeds seem to be the issue).

Roughly 70-75mph with the engine under load I can feel a vibration in the floor, the passenger in the front seat can feel it as well. Slight humming/whirring noise as well. As soon as I take my foot off of the gas it's all gone. I heard it once earlier, too, probably around 45-50mph with low RPMs and engine under load again, but it's much easier to reproduce at highway cruising speeds.

It is rather cold outside today. Snowy and single digit temps up to the teens.


Did anyone ever get this problem resolved?

Mine: 2007 V8 Sport 4WD with 40,000 miles.