I removed the underbody tray on my V6 Omega to have a shuffty underneath prior to it's annual MOT and found large pieces of aluminium cooling fins.
Assumed they were from the radiator but on closer examination I found that they were from the lower section of the air con condensor (on the inside next to the radiator).
The air con stills works ok and the condensor has no obvious leaks but it is the original (1998 model) and I guess is one it's way out.
I also have another Omega (1997 model) so I checked it's condensor. Guess what? Exactly the same type of damage!
So well worth checking. I found it easier to remove the centre plastic cover at the front of the engine bay and look down between the radiator and condesnor.
Looks like it's going to get expensive