I also own a 2006 Kia Sedona and as strange as this may seem whenever I hear the noise that everyone is complaining about I make sure all the seat belts are slid properly into the holder clips. This seems to eliminate a lot of the noise. On the whole this, to me, is a small price to pay for such a reliable car. I know the trade in value is low but I brought it for the long term and will not sell it until the cost of maintaining it exceeds an unrealistic level.