At yesterdays NEMO meeting, Paul showed me a newly appeared stress crack on his MCS:
This is the first stress cracked windshield I have seen, and it looks quite clearly not caused by any object hitting the screen. This issue seems to affect a number of MINI owners, who have had multiple windshield failures – yet I and other owners have no trouble at all. Very strange.
The good news is that MINI appears to be doing something about this issue – this recent North American Motoring post discusses a new windshield part coming, and this post even lists the new part number(s): 51-31-7 146-544 WINDSCREEN GREEN (different p/n if you have rain sensing wipers).
Chase your dealership for the new part; time will tell whether this new design solves the problem for those who have suffered …
M&I / GBMINI 
Could not believe your picy of the stress crack on ‘Pauls’ MCS we have an identical one on our MC which appeared yesterday (overnight it seemed). We havent been in contact with BMW yet but should get to them Monday or Tuesday.