OK, I have been hearing a LOT about this 70 MPH vibration. What does it feel like? Is it a "Noise" or can you "Feel" it???????? My truck has a rear end whine/drone at 68-70 MPH... . Once you get it to 71, can't hear or feel a darn thing. Same thing if you are less than 67MPH... . I don't think mine is a vibration. I have heard the vibration you can FEEL and makes your foot go to sleep on the throttle??? Someone please explain this VIBRATION..... THanks!