Apparently Mini has made several airbox versions for various countries and so far K&N only released one type of panel filter, sorry, not the one for your car!
Give them another few months and they should have it sorted out.
I just replaced my standard air filter with the K&N one (on a R56
MCS). I must say there is not much noise difference as with my previous Peugot 205 or VW Golf and Polo, guess the turbo's noise has everything in the engine bay muffled up. there is however a slight gain in throttle response and this will be even more noticable if you turn on the optional "Sport" button!