I hear what you are saying. But 10-15K oil interval per BMW is nuts . I've done every 5K on both the X and the 540i. 96 pickup and my old honda got every 3K. I've done this kind of maint. on every vehicle I've owned. My truck has 173K, wife's old honda had 279K when sold, 540i has 175K and the X5 is at 94K. Not trying to compare BMW with chevy or honda. BMW also claims lifetime fluid on tranny and differential(atleast on the older ones, not sure what the new standard is), which I never trust. People are amazed when I pop the hood on all the rides and tell them the actual miles on them.

Really it is up to the owner. Everyone has a preference on car maint. Me, I love to tinker with cars. Grew up around cars and drag racing. So I pretty much live and breath cars. It truly is amazing seeing and hearing people that just get in the car and drive and never check issues that arise or take care of their car. Not saying that people here do that, but just from personal encounters and some friends that just don't take care of their car. then they act all surprised when their car breaks down.

Sorry for the long post, don't mean to thread jack. Just try to share my personal experience when it comes to car maint. By all means I'm not saying go by what I've said or do what I do. just my 2 cents.