Having owned both Japanese and German cars (currently BMW) you have to keep up and stay on top of maintenance on German cars. They're just not the same as Japanese cars where you can get away without having to do something at a set interval.
And as "refined" as I find BMWs (or Euros in general) it's the stupid little things that go wrong make me think "Why did I buy this POS!?" Then again, I still like my M3. The E91 - not so much.
The example of the MKII VW hitting 500,000km - everybody says that but how much stupid shit went wrong along the way? On a Civic or Corolla? What, a window regulator went bad and it probably needed new shocks and an oil change here and there and still managed to squeeze 500,00km on the same motor before the rebuild? *Shrug* My E91 - what a piece of shit. CEL or some warning comes on every fucking time I start the car. But is anything really broken? No. So for fuck sakes BMW, throw me a bone. I'm a very particular owner for all things mechanical so when my CEL shows me that my tail light is out (but really, it's not) it drives me crazy. I can't accept this nor can I shrug it off. My E36 isn't the same. Things just work as-is.
I'm not trying to deter you from getting a BMW or trash talk Euro cars but if you are coming from an FX35 to a 2000 BMW 323/325i, you must be prepared to accept the reality that things
will go wrong during your ownership. Not if, but when and being prepared to accept this for what it is. Some people can't accept this as part of Euro ownership and vow to never buy Euro ever again.