I didn't take the time to look up the 11 digit part nbr you listed in your original post...but after looking up BMW part #
65 12 6 988 275 ...this is the radio receiver for BMWs with the Nav monitor.
BMWs that have an in-dash CD or cassette unit...the radio is incorporated into the CD or Cass...the radios like the nbr you posted are ONLY for BMWs that have a nav screen...this is their radio receiver. The other set-ups...as previously mentioned...the radio receiver is incorporated into the in-dash CD or in-dash Cassette player.
I'm not sure if this is answering your question...but if you use the BMWfans.info site (click link below)...it will list the old and/or new BMW part nbrs that are related. In this case, you can click on the "i" after the old (discontinued) or new (superceded) BMW part nbrs that are listed...to see what models they are associated with. Keep clicking links until no more are available...and you can find all the models that used the NLA (no longer available) part nbr and/or the part nbr that the unit replaced:
http://bmwfans.info/parts-catalog/65126988275
Using the 2 online BMW part databases given in this thread (realoem.com & bmwfans.info) you can plug in BMW part nbrs using these site's part nbr cross-reference & search features to find out lots of info about the models and date ranges of BMW components and other models that it may have been used in. As you see in thins example, sometimes a new part nbr doesn't list a BMW model if it is no longer being produced...but if you plug in the old (NLA) part nbr, you may find other BMW models that may be compatible when they were in production.
This is the radio (BMW53) used in the e53 (I used the VIN of my 06 E53 X5)...and it's BMW part nbr was
65 12 6 976 962 and was replaced by BMW part nbr
65 12 6 988 276: