I have been dealing with a waterpump noise issue on my R56 but after describing my problem noise to the chap at the dealers, he thought it might be the flywheel/clutch making the noise, he asked me if it gave a sort of bark while changing in high gears ( 1st, 2nd) when the steering was turned, he told me it was a known problem that mini were working on (don't hold your breath to long for a fix)
I don't know if this helps you at all it certainly didn't for me because its my waterpump which is acting up!! Totally different noise!!
