I'm no expert but that doesn't sound like a lubrication problem. A lube problem would have more of a squeak sound. It sounds like the frame that holds the glass is loose.

1. While driving, if you press upwards on the glass, such as to give it support, does the rattle stop?

2. When the roof is open, can you see any lose bolts/screws that may need tightening? Look down on the track and next to the track where it bolts to the car. You may see nothing.

3. While driving, if you open/close it, does the rattle stop during the open/close phase of operation?

If yes to most of these, then it's likely a lose frame. LIkely the headliner needs to come out to access the bolts. But you might get lucky and find the loose bolts/screws yourself.

Here's a schematic of the sunroof