I've not noticed this myself, unless there is actually bad traction (fast cornering or cornering over a grid/pothole)
Wish I had known about this sound earlier, I hope it is interesting!.........Then again maybe not, I don't want to be tempted to force it.I first noticed it a couple of months ago when I enabled the sound in My Green Volt app for when the mechanical brakes are applied.
That's better then Volvo's XC70 (first model, 2000-2007?) where the middle differential would be damaged if I remember correctly...I know my Subaru had to have tyres within 5mm same diameter else the VDC system started to flag up issues too.
Thats very similar speeds to where mine gets in a knot. I have a 270 degree snail shell shaped off ramp from my local motorway with slightly negative camber and a rough surface. The Ampera will go round smoothly at 40 mph but will jab the inside rear brake quite viciously at 42 mph. The Leaf however will take the same bend very comfortably at about 55 mph without any sign of traction control intervention.If I tip it in at 42 it will bong the brakes on mygreenvolt and the dash light will flash. If I do 40, it usually does not. Turn the stabilitrak and traction off though and it is fine.