I've looked for a thread detailing this "fix" but couldn't find anything. Last night when driving home from work the wife and I did some troubleshooting and found that the vibration sound is coming from the shift knob itself. If you remove the shift knob, the vibration goes away. I'm going to try some stuff this weekend to get rid of the vibration sound and let you know how it goes. I did find that if you tightened the knob all the way down the sound goes away, but then your shift gate pattern is upside down.