Been researching this symptom. Apparently, this happens from a lack of retracting the roof. I have been told that the roof needs to be retracted frequently to avoid this problem. Has anyone had this problem? What is the cause? Lastly, a guesstimate for cost of repair? Thanks. This is the last thing this car needs since I purchased it at the end of June 2015. I have spent about $5200.00 to get the essentials fixed. For a 2007, it only had 35800 miles; but I was surprised at how many essential things needed to be done. Thanks for your comments.