[Bill S]

Every BMW (& Merc & Audi!) I have had over the last 25+ years has been able to start after being left for several weeks without running. I have never been told that a car has to be run hundreds of miles every week to remain usable.

I cannot accept that the X3 is being hamstrung simply to satisfy legislation - it cannot be beyond designers abilities to include a simple software switch that could be used before storage/log term park/parking in extreme cold that would result in:
a/ the battery being fully charged/disable BER 60% mode.
b/ all ancillary circuits other than alarm being switched off when locked.

Surely that would solve the problem ... and if so that could be fixed now on all existing cars.
Would that not be simpler and cheaper for BMW than continuing to have call-outs to cars that will not start and replacing batteries that have failed due to being left with no charge?

This would seem to be a software design fault and software can be reprogrammed.