Do you have a set of winter tires?

That keeps me mulling over: the don't-let-me-get-stuck option is as easy as fitting the rear with the wheelspeen detect portion of ESP and powering two cheap electric motors in front: this will allow for 325/330xi style of awd-when-you-are-stuck without the prone to 2wheel dynamometer and luddite with a two truck damage to the subaru bread and butter symmetrical setup.

The more I think of it the less I want permanent all wheel drive. I want a classic rwd most of the time and more so when it's slippery to allow for course correction and fast rotation with gas pedal.