I'm not sure if this is a defect or part of intended engineering. When the ventilation system is directed to just the floor heat setting there is the sound of rushing air coming from the defroster vents. It's not noticeable at highway speeds, but is noticeable when stopped. Interestingly when the vent is directed to the defroster there is no air sound. My conclusion is that the rushing air sound is caused by the defroster vent being opened just crack when heat is directed to the floor. My question is....is this small amount of air leakage to the defroster intentional....or is the defroster vent not closing properly? I could envision that Toyota felt that any time you direct air to the floor (cold weather) you would also want a LITTLE air to the defroster vent to keep the window clear. But then again, they give you a combination floor/defrost setting so I'm not sure why they would do that. Thanks for your input/comments!