Updated with correct info for future reference (since this info wasn't all that easy to come by)!
2009 - updated navigation with internal hard drive (much) improved interface, new tail lights (sedan only)
2010 - standard HD radio and optional automatic headlights. [edmunds]
2011 -
"2011.5" (Sep 2010)
-Extended bluetooth:
- streaming audio over bluetooth,
- mobile office: email, text messages and notes displayed and/or read aloud
- external call list downloaded from phone
-iPod adapter updates (new Combox hardware not retrofitable to older models)
-No longer need Y-cable, use standard iphone usb cable, streams music digitally from device
-Album cover art displayed from metadata in track
-Voice command control external devices and select genre, artist, album, and song title by simply speaking the words.
-Mobile phone device driver update with BMW Assist (sounds stupid and wonder if this costs for their service)
- Competition package that adds a 10mm lowered suspension, 19-inch wheels w/ performance tires, reprogrammed electronic damping and stability controls.
- M button - programs your M settings - set the drivers preferences for Stability Control, Steering mode, Shift light, EDC, and if the car has the M DCT the Drive logic mode can also be set
- Automatic/Start Stop - car shuts off at complete stops, button controlled option (defaulted to Off on US model, On for euro models)
- Manual M Sport Seats - Remove electronic seat for weight savings. Lumber support and seatback side bolters remain electrically adjustable.
- New Mineral White Metallic paint is available
- New LED tail lights on coupe
- Leather option changes, Premium pkg 2 (adds power front seats), new Convenience Package replacing technology package
"2011.75" (March 2011) - BMW Apps integration (pandora, facebook, twitter etc)
2012 - None