My wife is complaining that her sunroof is becoming hard to open/close. I am not surprised as she was also complaining that her driver's side rear door was having troubles opening/closing as well as the window in that door. I opened the door up and lubed everything and now the door is fine. So I am thinking I need to lube the sunroof as well. I was reading my Bentley book and see where they say to lube the sunroof tracks. But they also say to use only a special grease. I am sure that some greases would be better here than others. But I find it hard to believe that I MUST use a Volvo grease. Any comments on what to use and what to avoid? Thanks.