I have had a similar issue now 2 times with my 2013 X3 (with the Msport suspension). I had the warning "chassis drive moderately" pop up intermettently over the span of a month or so, then it started happening daily, so I took the car to the dealer. They did something, not sure what - I think they just re-set the computer, sent me home, and the warning came on as I was driving home from the dealership. So I took the car back and they replaced a sensor.
That was two months ago and the problem seemed to be cured...until today. When the warning came back again.
It seemed like they didn't really understand what was causing the problem or quite how to fix it. So we'll see if they have any more insight this time around.