From NYTimes Auto's 12/15/12:

"MINI Oil changes in Minis may become a bit more complicated. In T.S.B. M110612 issued on Oct. 1, Mini’s parent company, BMW, said that technicians might find an O-ring in the oil filter housing when changing the oil. The O-ring is from the oil filter nonreturn valve inside the engine, and it dislodges because it is too small. BMW said that no further engine damage was caused by the O-ring, and that replacing the oil filter housing should clear up the issue. The problem can occur in 2006-12 Hardtops, 2009-12 Convertibles and all years through 2012 of the Coupe, Roadster and Countryman."

Forgive if this has been discussed here already. Anyone with experience with the issue in this TSB, or replacement oil filter housings - is there a part # associated with a revised housing that's updated with proper o ring?

 

Here you go, it looks like they finally figured it out:
https://www.northamericanmotoring.co...nd-o-ring.html