I realize this is not a new topic, but just a friendly reminder to new 6MT owners -- make sure you ask your service advisor to ensure they actually changed the manual transmission fluid during the 1,200 mile first service.
I just had my service done on my 2013 6MT - and sure enough they didn't change the manual tranny fluid. Manual transmission fluid wasn't listed on the receipt and when I asked a question they said "we don't change the transmission fluid on the M3." I showed them the service/maintenance booklet that came with the car (page 7) and they realized their mistake. They'll be changing the manual tranny fluid tomorrow.
So, new 6MT owners, please make sure to ask the question and confirm they did change the manual tranny fluid