As most of these cars have a giant relay junction like our W210 have a unit called K40, can it be that the source of power is from there ergo no activity in the key switch.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)