Strange noise after driving a while s3


Registered User

Picked my new 8p 2007 s3 up last night, all was good but driving along motorway for 20 mins or so and could hear a faint whiring noise? Sounded like climate control I thought as my brothers Bmw does it sometimes, anyway turned it off, noise still there, turned radio off, still there and slowed down and sped up, still there!
When I come off the motorway and came to complete stop, the noise stopped and didn't come back when I set off,
It's did come back however after a further 20 mins or so driving again!
Anyone any ideas?? Ha car drives fine btw too