I can't speak specifically to the newer generation, but I can share our experience with a previous generation; a 2004 325i (E46 model). It was purchased new by my brother-in-law, purchased by my in-laws at 25,000 miles and we acquired it at 74,000 miles. There had been nothing other than routine maintenance required and they did it consistently.
After we got it, it immediately needed new belt pulleys, then developed a valve cover gasket leak and an oil housing gasket leak - paid to have them done. The Throttle Position Sensor failed - replaced it myself. A coolant leak developed - ultimately replaced the radiator, hoses, thermostat & housing, expansion tank and water pump myself (all at the same time). Then it started blowing billows of white smoke, indicating the Crank Case Ventilation system was clogging - replaced CCV valve and hoses myself when I did the cooling system. Both the passenger and driver window regulators failed - replaced them myself. All of this happened before 100,000 miles. Most of the forums I reviewed indicated that these are "normal maintenance items". Doing the work myself was challenging (gotta love YouTube), but saved at least $3,000 based on quotes I received. My retort would be that it's not "normal maintenance" on my Honda Civic, Tahoe, Suburban, etc.; all of which have well over 150,000 miles on them.
Don't get me wrong; it is a pleasure to drive. But I also noticed the value go down quickly after 75,000 miles and there were tons of them listed for sale with less than 100,000 miles.
For anyone who is deadset on a BMW, stick with the 3 series with lower-level packages (less to break) if you plan to drive it a long time (get the extended warranty too). Otherwise, lease it and get rid of it before 75,000 miles. (PS. My friend had an '05 Audi A4 and it was much worse. The newer ones are starting to get better reliability reviews.). Needless to say, the BMW replacement will be a Lexus/Toyota or Acura/Honda.