For the last couple months of owning my rig, this rattle has driven me to the point of going out and buying an entire new sunroof assembly so i could play with it and determine what the rattle was off the truck. (And I robbed the glass off for a different 4runner, so I needed the assembly anyways). Well, I think I found an easy solution.
I started off my greasing the channel documented earlier in this thread (#1), and that didn't help. My rattle was coming from further back. After playing with this assembly, I found that the hinging mechanism had lots of play, where the pin is in the "wavy" channel, as well as the base of the triangular support. So while the sunroof was closed, I removed the two plastic rail covers, took some thick lithium grease, and squeezed it into those two spots, and for the last few days, my rattle has been non-existent. Only time will tell if it is long term, but so far, so good.
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