I have had over the years 3 – 3 series, 3 -5 series and 2 – X3’s and 2 – X5’s and currently own a 2018 4 series 420d. All have been serviced regularly and with no major issues, mechanical or electrical. My brother is on is 9th 3 series. I don’t recall him having any majour issues either. My niece had the last one off her father, which is now 6 years old. Like anything in life, look after it, it will serve you well. @BigDave, @Elliot, @Glos Guy have most likey had more than me over their life time.
I’ve had 3’s, a 4 series, a 5 series, 1 series, X1. Never had a problem with any of them and the dealers have mostly been first class. My wife has a Mini which is a BMW and she loves it too. As an ex company car driver, I driven many other brands so I’ve been able to compare and the BMW’s have always come out on top.I do wonder where this hate of BMW comes from.