I dunno if its normal since I just noticed it last night while sitting (idling) in a Taco Bell drive thru.. but when I put the trannie in manumatic mode, I heard a high pitched whistling noise coming from the bottom of the car.. the noise goes away instantly when I put it back in D.. it sounded kind of like some kind of vacuum leak because it wasnt a consistent "pitch", if that makes sense.. I listened for it later with the window down and I could still hear it, but its much much harder to notice since there wasnt anything refecting the sound..

I was planning on taking my car to the dealer anyway.. but was wondering if anyone could shed some light on this.. is it normal? is there anything remotely related to the trannie that would produce a vacuum leak or a similar sound?