Yes, worked out that it was a squeaky windscreen seal. You can test it by sitting in the car and pushing firmly against the top section of the windscreen. If you hear the noise then you need to apply silicone spray to the seals. Holden are aware of a fix and can do this for you at next service. There is a thread dedicated to this topic if you do a quick search.
I've had my Calais back 3 times for them to fix the squeaks and rattles since they pulled the dash out to replace A/C unit, had enough and went there yesterday and said fix properly this time, mechanic went with me and heard the noises, so will let you know next week when I drop it off.