That is why they have issues,because they are complicated.If BMW took 5 or 7 years to perfect a certain model no one will buy it because it will be out of date and terribly overpriced.But as a matter of fact the last years of any model are pretty much trouble free.
Take older Lexus or Acura,they are stripped as a Toyota Echo and not much fun to drive,but reliable.Newer models of those brands are much more complicated and if you think they dont have their problems you are deeply mistaken.