i have a 2012 mini s... it started doin it at 2000 miles...its got 4k on it now...does it when its cold...start it up and it runs rough and almost stalls......it has zero power when u first drive it down the street..a few minutes and stumbles it clears out...my guess...injector issues....either they are leakin a bit when cold...or its an issue with the ecu...

 

There are a few recall / campaigns for your 2012 MINI S which would cause those symptoms. Get it back to them so they can perform those services....

 

Car is underwarrenty....
So get it looked at, and reported....hopefully fixed on the first try!!
the sooner the better imo, espically since it should be a free fix.

 

the dealer seems real good here....service guys told me I can do what I want and they will cover it...just to bolt on a gt28 on it! I would like to make more power...but i havent found a reflash that seems good...not sure how much they are worth...I do alot of reflashing for bikes...but i cant find anyone to sell me the software and cable