I have an '06 2wd hemi with 16,500 miles. When I am in drive, with the brake fully depressed such as in line at a drive thru, there is an intermittent vibration that can be heard coming from somewhere either in the dash or under the hood. It is not continuous but will last for a few seconds and go away for a few seconds then come back. It only happens when in drive with the brake pedal fully depressed. Let me know if any of you have experienced the same thing.