I should also reiterate- these issues are all 100+K issues, if the car has 50K and is in a more reasonable climate than say, AZ the car will likely be solid indefinitely. My experiences aren't the type that will leave the car stranded-, in that sense the E39 is loaded with annoyances, but none fatal. I see them as robustly built, solid cars that can easily hit 200K plus with reasonable upkeep.
Well- one time I did manage to dislocate the axle from the pumpkin when I went balls out one day- but that's typical with any BMW that's
tracked, or if you treat a 4000LB car like a 911. You have to take a hammer and drift and slip it back into the diff, rare, but it happened to me - ONCE.
If you really want a high maintenance scary experience I recommend an 2004 + Audi S4 V8 with the timing chain BEHIND the engine that typically goes kaput under 100K and requires full engine removal to rectify- see for yourself. In relation to THAT car, ANY E39 s a Honda.
I plan on keeping my 540I until the end of time, or until my next craving which will likely occur in 15 minutes or so...
rjp
PSS- I should also clarify the suspension- I lightly drive my cars, I don't beat on them- the ONLY suspension wear pieces that honestly needed replacement are as follows, on my 530I, owned from 20K to 101K
80K- front control arm bushings. You can tell when the car has a shimmy around 50-60 mph, and / or you tap the brakes suddenly at low, low speed and the steering jerks in your hand. Common problem and easy fix on these cars.
On my 540I, purchased at 140K it had:
replacement meyle solid bushings, probably at 80K- I don't like 'em, but they were in there so I leave them for now.
at 155k I needed new front struts- and THAT'S IT, back were still serviceable, but I replaced them anyhow, All the rest of the ball joints and links, still solid. I replaced my rear ball joints, and rear upper control arm (very easy) not because of joint failure, but the boots tore during my inspection. Had I not done that, I seriously think I would've gotten close to 200K out of the rest of the suspension, including the upper strut mounts and other disposables. Strut replacement is easy, despite what people think- see here:
http://forums.pelicanparts.com/bmw-5-series-e28-e34-e39/792881-freaky-lil-discovery-today-rear-struts-03-m-sport-sachs.html
So, apart from front control arm bushings, and front struts were all my particular car needed. The other parts I replaced like the rear upper control arm, and ball joint were just while I was in there.
My car drives like new, and even my wrench who I go to if things get too hairy is impressed with it's condition and the drive quality.
Rjp