I am trying to figure out why I get cold air from the middle knee vents all the time, except when at a complete stop. It doesn't matter what position the levers are set at, or at what temp, nothing changes. I remember I ran into the same problem with the last Porsche I had, as it had a mixer box under dash with a cheap plastic latch that would break over time, letting in outside air continually. Do these cars have a mixing box or something similiar that fails, letting in outside air all the time? At this rate, I can't wait until summer comes...