I have a severe vibration over 65 mph that comes and goes while staying at the same speed. Car has no bent rims or rotors, they are all new. Also replaced a hub that may have had a flat spot in the bearings. I would prefer not to drop it off at the dealer and ask them to figure it out.$$$$

 

Are you sure your tires are perfectly round. I got a set of Firestones one time from Tire rack that were not round and had the same symtoms.

 

Double check the balancing, maybe even try a shop that does the roadforce balancing.

Is the vibration in the steering wheel or does it feel like the whole car is shaking (ie from the back)? I had a crazy intermittent vibration at highway speeds as well and it turned out to be a blown rear differential bushing. They leak goo when they go bad, so it should be pretty obvious if you look under the car.