I have a BMW 2006 e53 3.0i and have never had any problems other than minor ones? I never submit it to hard driving, have taking it through country many times with my dog and daughter in the back and my wife in the passenger seat and we have enjoyed 1000s of miles of trouble free operation for 6 years. I clean it regularly, have it checked by an authorised BMW dealer every 6 months and once a year, it has its service.
I am despaired about the problems people are dealing with on this forum. It has never been my BMW experience and I've had BMW cars for the past 20 years? I never buy a BMW unless its from an authorised BMW dealer who guarantees the car has passed a 100 point check. However, many of the models on this forum have been purchased cheap through private sale or non BMW dealers who don't submit the car to authorised checks. The cars have probably been abused by the previous owner, not cleaned or serviced regularly, and have just been at the device of a driver with too much money and brawn for brains.
Your car may have had this history?