well, I was treated to a very unpleasant experience this weekend with my truck. As soon as i went over 55mph, there was a very high pitch noise coming from someplace within the truck. It was starting to hurt my ears, and no matter how loud I turned up the music, I could not drown out the sound. As soon as i dropped below 55, it was nice and quiet. Gonna be calling the dealer tomorrow and find out what's causing this.