One problem related to driveshaft has been reported for the 2014 BMW 650. The most recently reported issues are listed below.
During routine service last month, local BMW dealer found the drive shaft rear guibo/flexible disc was cracking and recommended immediate action. It's the same problem as was recalled on other BMW models (see recall campaign 17v-067). I reported it to BMW but BMW refused to take any action or to assist. Cost to fix is almost $1000. The dealer informed me that if not fixed, the drive shaft could separate from the vehicle. Yikes! I believe BMW should fix/recall this. The original msrp on this car was over $103,000 - in my opinion, this defect should not happen on such a car, especially at only 57,000 miles.