2015 Focus SE with a manual trans. 99k miles. Thursday I decided it was time for new tires, tech installed them and we replaced the thermostat at the same time. I live roughly an hour away from work, and noticed a vibration on the way home at highway speed. I assumed maybe the balance was a little off and I'll have him look at it again when I go back to work. This time I asked him if he could do a road force balance just to make sure. He literally spent over 2 hours making sure that they were spot on balanced. Now the vibration is worse. Seems to get worse with more speed. Seems fine at 25-30 mph, and idles fine. Could it still be the tires?