If you have a MY11.5 then chances are it already came loaded with the latest iDrive update, and you probably already have the 231E software that you're referring to.
And yeah, the phone ring in the M3 is incredibly loud, isn't it?
'09 E92 M3: Space Gray, Black, Carbon Leather | ZTP 2MK ZPP 2MT 6FL | link 1 / link 2
Mods: M Performance exhaust | ZCP retrofit | Euro airbox | GTS DCT flash | 240J ECU flash | LCI Euro taillights | CRT lip | OEM alarm retrofit | Space Gray bumper plugs | BMW Performance: Mk. II spoiler / Mk. II non-electronic steering wheel / mirror caps / front grilles / side gills / intake louvers / emblem