To update on this....took to mechanic this morning and of course couldn't hear anything. Left car there for the day and still couldn't hear anything. I described the noise. Said it only lasts 1-2 minutes. Mechanic seems to think it could be the oil in the hydraulics (?) and once warmed up, it seals (?). As it's only a brief noise, it's nothing to be concerned about but if it's ongoing, then there could be a major issue. He said that the hydraulics would need replacing and that can be very expensive.
Suggestions on approximate cost if this is the case?
Tomorrow morning I'll try and record the noise if it'll pick up, that way he can hear exactly what it sounds like. The other option is to leave the car there overnight so he can hear first thing in the morning when the engine is cold, but as I work in Melbourne, it's not possible.