The SA at my local bmw dealer told me at 100k they recommend the transmission fluid to be changed (even though the pan states lifetime). If the dealer you go to doesn't want to do it, just try a different dealer.
If no codes are being thrown use Chevron Techron fuel injector cleaner (concentrate). It solves rpm fluctuating upon cold start-up. Also, for most BMW problems start off by scanning your car with the Peake Research Tool. It contains the actual BMW codes. If you want to register a newly installed battery for free (just buy a $10 cable) and google/download BMWLogger