There's a certain thin range of voltage that is bad for BMWs where the instrument cluster goes haywire, and that voltage is in the opposite of the Goldilocks Zone.
That is, instead of it being not too hot and not too cold, which would be a good thing for a Goldilocks Zone... the voltage is just a tad not low enough to cause the car not to start but just low enough to cause the instrument cluster to go haywire.
What would you call that thin sliver of a problematic zone?