Need a Mini-help...

Hi to all of you! A friend of mine has just bought a brand new Mini Cooper Checkmate - I don't know if it's just a special edition for Italy: it's a Mini Cooper with some cosmetic changes. I need your help because on the dashboard there's this button: my friend says he hasn't found out in the instructions what it's about. He got his Mini with the optional "dashboard-packet" (I don't know what is its name, neither in Italian or English): behind the steering wheel there's not only the rev counter, but also the speedometer. However, he says that THE button is in every Mini - I think he's right. What I'd like to know is: what's the button's function?... My friend even tried to push it, but nothing happened. So, thanks if you can help us!