I think the most reliable engine BMW ever made was that small I6 they put in the 3 series before the change over to forced induction
I was eying a mint 1 owner 2011 BMW 328XI with nearly 71,022 miles, and I'm still hesitant on trading in my Chevy Cruze (loves this car for what it is) for it
They also have a 2013 BMW550I MSport with 86,000 miles for like $36,000... (talk about resale value)
I really want this car but that twin-turbo V8 is garbage and thirsty from what I read on the bimmer forums.. it will stay in the shop, So I can afford 3 series maintenance.. if I can take apart a Pratt & Whitney JT8 than an NA I6 should be cake, but 5 series maintenance would bankrupt me lol with that high pressure fuel pump, twin-turbos and valves crapping out