this seems to be a common issue with crossfires. i have had the same problem. there is a creaking sound that comes from the panel that the seat belt emerges from. the small plastic trim piece that serves as the guide for the seatbelt also can cause a creaking sound. i had it "fixed" by a dealer on two occasions. it is only marginally better. it gets worse when the interior is hot in the summer. the problem is that there is no insulation between the trim piece and the panel and no insulation between the panel and the sheet metal. any flexing of the vehicle in this area or expansion/contraction causes the parts to rub slightly resulting in the creaking noise. more recently i've also heard a slight rattling sound coming from inside the rear part of the door. i'll eventually get around to fixing them myself. listening to the radio tends to temporarily "eliminate" these noises.