OK - well I have been going through hell with this. Put on new Michelins last year and they never could get the vibration totally out at 50-70MPH - went several places, just lived with it. Just put new Hankooks on and the issue was worse, They changed one of the tires. They checked the wheels and anything they could think of. I finally went to a custome wheel shop with a pretty serious road force balancer and they got it out - most of the time. It is so strange, but it seems like it gets worse when the air conditioning is working.When they are cool (tires) they are wonderful. I go to work in the am and hardly feel it. Leave office in afternoon and as soon as I pull onto highway the steering wheel starts junping back and forth. Have repacked the bearings. Have changed brakes and rotors...it is the most annoying thing I have ever experienced on a car.