When putting the roof up on my 2012 XKR convertible a loud screeching sound occurs. I haven't been putting the roof up and down lately but today was nice enough. I don't have the time to take it to the dealer to get them to look at it at the moment (testing the new S-class and the GL-class tomorrow ) so I was wondering if any of you have had this issue on your car and could explain what was wrong with it, and the cost to have it fixed.