A buddy of mine has an '85 BMW 325e with well over 500K on the original auto tranny, the engine blew a head gasket a few years ago, he did a valve job and replaced the head gasket. The tranny has never been opened.
He beats on the car pretty hard - he got it new in high school 20 years ago. The odometer stopped working in '91 with 180K. At the time his commute to college was 160 mile round trip 3 times a week. in the mid 90's he drove it to california. for the last 10 years he has been living in mojave, and drives to L.A. everyday for work. It is about 100 miles each way every day. just commuting that is 50K a year. He has been doing the commute for 10 years.
The body on the car is in decent condition, the Air conditioner has been repaired a couple of times, the power windows have stopped working on occasion.
He changes the oil every 6 months with 20w50 dino oil. Obviously it is lots of highway miles.
He has been talking about buying a new car for many years, but he is convinced that he would rather drive a million mile bmw than a new accord. He has considered a new bmw 330, but fears that it won't be as reliable as his old one.