Nearing 25k on my 2018 540i xDrive M Sport. Still feels and drives like a brand-new car. And it still brings a smile to my face every time I take it into the twisties....
I often take 400 mile trips down the East Coast. It is just an absolutely wonderful cruiser for these trips, eats up miles like they're nothing. You can easily do 100 mph all day long in this car (although I wouldn't recommend it in the States). It feels perfectly planted and solid all the time.