Originally Posted by taibanl
This shouldn't be the case. I have spoken to the BMW Product Technology Manager about this exact issue who stated "The 335d should ALWAYS make the scheduled service interval" before requiring DEF. In some cases such as frequent towing, the X5D MIGHT not.
You may want to discuss this further before accepting this situation.
I can see the principal behind this, but there is somebody out there in a 3 series that drives very aggressively that will need a DEF top off in between services. I know our loaner car 335d in service (BMW dealership) needed its first oil change at 8500 miles and was stating low DEF. So it was close, but did not run out before its scheduled service.