I just had a vibration above 70 mph, new tires, balanced to perfection. I traced it to the front left and found 3 spots about 3” long of old white sticky residue. Cleaned it off, removed the old weights and cleaned that. The shop was starting with a clean canvas and Problem solved. My theory is that the extra gunk wasn’t showing up on their hunter machine but showed at high speeds? That’s really the only thing it could have been. Rims were true and not so much as a spec of curb rash. Of course this car sits at 115k and is on its 3rd set of tires, so the weights have been installed and removed a few times.