Thanks for the link. I have copied the SIB to here so that it is on this site, and searchable. It is reference SIB 01 04 10, dated August 2010, and replacing SIB 00 01 04 dated 2001.
If you do just over 6000 miles annually, it appears you will get the condition based service indicator at the 24 month marker. If you drive between 6000 and 7500 miles annually, you will either hit the 24 month marker, or the scheduled change at around 15,000 miles. If you drive more than 7500 miles per year, you will likely hit the CBS indication before the 24 months, based on fuel consumption and other factors.
Interesting that the scenarios (examples) given in the link are down to the day, and mile, in terms of qualifying or not. Scenarios are attached below as a pdf.
__________________ 2007 X3 3.0si, 6 MT, Premium, White