Well after waiting few weeks, Mini finally emailed me back today .. here is what they say on the subject :
Dear Neil
Thank you for your email to MINI Customer Information, and please accept our apologies in the time taken to get back to you.
The bonnet scoop has not been unblocked for 2008 model year MINIs, the mesh of the scoop was changed in 2007 in design however the vent is still blocked. The engine has more than sufficient cooling with its current set up which is why it is unnecessary to unblock the vent.
We trust this information is of use and please feel free to contact us should you have any further questions.
Yours sincerely
Christian Gorton
MINI UK
Product Information Advisor
Ellesfield Avenue
Bracknell RG12 8TA