Has anyone noticed a harshness while accelerating moderately (spirited but not past 60%+ throttle) around 2nd and/or 3rd gear 2200-3200 RPM? I'm assuming it may be the same culprit that is making the whistling noise. Its rough enough that passengers this morning said, "why does you car have so much vibration and we aren't even going that fast!?" It's bothersome and it does not seems liek an exhaust sound. Its not really a sound at all, but a vibration felt through the seats/dash, ect.
It goes away once cruising and does not show up if I rev it in neutral. Only under load.