[apollner]

It's happened to me a few times. I'm at a traffic light, I have a car behind me, and I sense what feels like someone bumping me ever so slightly from behind. Then I look in the rearview mirror and see that the person behind is not close enough for them to have actually bumped me.

I think what is happening is some sort of resetting or rebalancing of the torque distribution between from and back wheels. I'm just guessing, I really don't know.

So the last time it happened, I took conscious note of surrounding variables.
a) I had my foot firmly on the brake pedal.
b) I did not feel any modulation on the brake pedal.
c) The car had the Sport button depressed.

I state the above, because on previous occasions when this happened, I did not remember if my foot possibly had released some pressure off the brake pedal.

The feeling is somewhat similar the the slight "nudge" you get when putting the car from park into drive.

Anybody else experience this? Any further thoughts on what could cause it?