I've also got a Bravo with the pano roof. Unfortunately, mine also has an issue but I took it to a sunroof specialist who adjusted the glass which got rid of the problem mostly, however they said the seals require replacement to completely get rid of the noise.
Didn't opt to go down that route as i'd think it would be expensive, so have just got used to shutting the blind which mutes it!
Can't say I know what that part is though!