Cue the remap that permanently enables "Drift Mode"...
On paper it sounds best of both worlds; RWD for when the mister is driving and AWD for when the wife is.
It will be interesting to hear from owners what it's like in the real world because even though the drivetrain can be customised there'll still be more weight and less turning circle on the front axle due to the wheels being driven, by the sounds of it the system is a more advanced one of my L200 (and other 4x4's) that can be driven either RWD or 4WD.
2015 R172 SLK55 AMG, 2018 BMW 530d MSport xDrive, 2018 Mini Cooper S
Of course it's a proper AMG. E class has had 4wd in other markets for years.
I think this whole drift mode thing is a bit of a non event....how many drivers go out on the road and turn their traction control completely off for a run in the country....now it's turn off 4wd and traction control, I'm sure the insurers would have some thing to say if you stuffed it in drift mode!!!!!