I just bought a 2012 A4 2.0T. I cant figure out how to change the trip computer form distance to empty to MPG. I have looked it up and everything says there are controls on the right control stick that also has the windshield wiper controls yet i dont have the buttons that they talk about. I do have 2 buttons up on the gauges. One says set and the other is 0.0 but it wont change.