I've had this problem, too. It's a creaking/ticking sound that comes from the top of the passenger rear quarter window. And yes, if I just barely "crack" the window open ever so slightly the sound goes away. But up all the way it creaks and ticks during my entire drive. I've had my convertible in service six different times for a total of 28 days (And I've only owned it for 3 months.) They've tried replacing seals, adjusting the window regulator and ordered & applied a special graphite lubricant from Germany. Nothing has worked so far. They called me today to have me bring it in on January 18th to have the window and regulator both replaced hoping it will resolve that terrible sound. We'll see if that fixes it...