Got my tires balanced for a 3rd time today, this time from a shop other than Kia. They found that both my fronts were out of wack and corrected them. It did drastically improve my ride, however, this still did not 100% make the vibration go away. I took my invoice to Kia and talked to the service manager. In 2 weeks when I'm in for service we are going to swap out wheels and tires with another Stinger on the lot to see if the issue still remains. If the problem is gone with OEM tires, I may be dealing with bad or out of round tires at which point I should be getting replacement rubber under warranty. If the vibration is still there, I have another issue on my hands. I feel it from 45-55mph then it goes away until I hit about 72. It's such a high frequency vibration that I bet most people won't notice it. Just like my crappy cruise control surge that nobody feels except me.