I am in the same wagon, I now have 55k miles on it and warranty expiring in 5 months.
I am wondering about holding or selling.
I actually placed an add to see interest and listed my maintenance history:
https://www.panjo.com/buy/2011-bmw-x...kage-fl-333205

I had 15k of maintenance done last year alone. While this was scary, I have to say that now that I have all the expensive items done may be I should just keep the car.

I have not read much about N63 problems aside of these usual problems:
- valve stems
- injector
- coolant lines / pump

Everybody is bitching about the N63, but really I have not seen anything else happening to these engine. There are expensive fix but aside of that I have never seen any catastrophic failure. I see a lot more thread on diesel engine failure...

I am curious to hear about high mileage N63 maintenance issues.

The car is such a joy to drive and now that is is worth $20k, there is really nothing on the used car market that can touch it.