I have a 07 Clubman, and they fold by pushing the top half towards the window. It helps if you look at the neck of the mirror there is a horizontal line, that is the fold line, twist there towards the windscreen and it should pivot!
As mentioned they do fold, if stiff a lick of WD-40 on the joint will free them up. I recon the stiffness you're feeling is because you're trying to fold them straight back. In fact they fold in a upwards motion. Hold the mirror with two hands cupping up and fold anticlockwise in a upwards motion as if pushing the mirror up to the door window, it should move quite freely, as gbwongy said look at the line at the base. hope this is of help
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.