I have a strong suspicion that this app is only for cars with the external "noise cancelling" (i.e. ActiveSilence) speaker, clearest discussion here:
https://www.bimmerpost.com/forums/sh...php?p=25707326
And in turn, that speaker appears to only be present on V8 versions of X5/X6/X7 (so not 45e, 40i, or any of the diesels which are all 6 cylinders with varying turbo configurations ... and only in 50i, M50i, and maybe the "real" Ms).