I have had only one problem to speak of, the rear flex coupler joint mounting the transmission to the drive shaft is supposedly unbreakable, and I broke it. This occurred right around 200 thousand miles.
This is certainly a high performance car. Its being rear wheel drive gives it an advantage on race day over those Japanese rice rockets. In addition, the cabin is comfortable and unlike some cars I have owned, the manual, and electronic controls through out the car are very user friendly. BMW knew what they were doing!
Those who told you the rear joint was unbreakable do not know what they were talking about/ Some BMW's have a CV joint in the rear and some have a you joint. Both of which fail at @ 150k miles and require a new driveshaft or a rebuilt one. Both of which will cost about $500+ USD to replace wiht a properly balanced shaft.
Good choice in cars, will easily last you many miles if maintained properly!!!