Any G650 operators seeing "smoking" (i.e. they leave a dark trail on the fuselage) rivets on the fuselage at various locations?
All rivets that are properly set will eventually "smoke" given a structure subjected to vibration that has been under-engineered, meaning not enough rivets per inch. The other cause would be improperly installed rivets. What looks like smoke is aluminum oxide produced by the movement of the surface, and the rivet rubbing a bit of it and sloughing it out and back along the airstream direction.