teep - thanks for putting me right here. I must have nudged it.
Jeez - I've had this car for 18 months now, and I didn't know that it had that feature! To be fair I have always driven a stick-shift, and I assumed that auto was literally just that.
One other thing, but not a real excuse, is that when in Drive on my Left-Hand drive version of this car, the -D+ legend is concealed from the driver behind the shift knob, as the bezel is the same at that for the US and Continental RHD models.
I will have admit that I had never noticed the +/- before. Now I will have to learn how to use it properly.