October 1999 flying Manchester to Gatwick (thence Phoenix, Oakland to join a ship in Oakland) noticed that most of the fasteners, Dzus(?) that secured a wing panel over the right hand engine of the BA737 were missing. When we landed I checked the left hand side and 100% present. Tried asking the cabin crew to pass on to the fight deck, but not interested.
Admittedly nothing was flapping or fell off during the 30 odd minutes MAN to LGW, but I'm sure the fasteners should have been there...