Hi mate, i had a similar problem to yours, only mine made a slight grinding noise aswell. From what i understand the "whining" noise is common and effects almost all the 350's. I was more concerned about the grinding noise. The best i could describe it was like two stone disks rubbing together. Anyway i took it back to the dealer (Westway Nissan) as it was only 2 weeks old and still under warrenty. I went in and told them i beleive my clutch release bearing is worn (armed with knowledge i got from this forum!! ) and the head Service guy come out, got in my car listened to the noise and agreeded with me.
I left it with them a few days later for a week, during which time they phoned me and said that it was the bearing, and that they would change it.
From what the guy told me it can be a ball ache for them because as its under warrenty, they have to get a head mechanic from nissan to come out inspect it, agree its broken and a warrenty issue before they can start work on it.
As people have said previously the Zed has quite a noisey transmisson and the whining sound is normal, although from what the mechanic told me its the slight grinding noise that indicates the bearing is on its way out.
Hope this helps!! Regards, Lionel.