Mine idles rough at low RPM as well. I don't hear anything out of the ordinary, but I can feel it rocking away. Could it be the rough low idle is a trade-off for the smooth as silk operation at high RPMs? Somewhat odd if you consider how may spark plugs this thing has, but who knows whats causing it anyway. You'd think they could write some software into the ECM to adjust whatever needs adjusting to smooth out the lower end.