Fleabag,
Mine started doing this around 35,000 miles. Exact same noise. Lubing would temporarily fix for maybe a week and only sometimes. Really it would mostly just quiet it down. I tried everything to fix it. Cleaned out tracks and relubed, had the dealer lube it, tried re-aligning the panels, had two dealers try aligning the panels. There were a lot of posts about the pano on CT but never could find one with this specific issue.
In the end I made a claim on my extended warranty to replace the sunroof frame at the dealer's recommendation. I was very hesitant to do this because it involved removal of my whole headliner. Glad I did it though--has worked perfectly ever sine and the dealer did a great job not damaging anything. If you're under warranty I would suggest the same before you're no longer under warranty. I really believe it was the only way to fix it... I truly tried everything on the damn thing and never could get it. Even spent $80 on the two fancy VW lubes... waste of time and money.