Getting a bad vibration throug the car between 50 and 60 mph had tracking and balancing done it became worse after the car had been up in the air with wheels dangling but then settled down again to the normal vibration
Was that balancing done with Road Force Balancing equipment, like the Hunter GSP 9700 machine?
If not, I would recommend doing so, as it can make a huge difference.
The high-speed vibration of the OEM Continental tires on my Outback was not “cured” with conventional balancing, but when the dealership bought one of these Hunter machines, the problem went away.
I had similar problem with Continentals and Dunlops.
Only “road-force” type of balancing was able to cure it.
It does seem like a wheel/tire problem. Another idea, try swapping the tires around, see if there’s any difference in the vibration and where you feel it. For example if you feel it mostly coming from the seat now, and it switches to coming from the steering wheel after a front/back swap, good chance the problem tire is now on the front. This also give you a chance to make sure the wheels are properly mounted to the hubs with the proper torque on the lug nuts. And you can inspect the struts & outer CV boots more easily when the wheels are removed. Likewise, inspecting for bent wheels.