Revised Symptoms:
Car has a vibration that cyclically runs through it when in D at a stop. If while holding the brake you rev the rpms up just a tad, the vibration goes away. Same when I shift the car into Park. The only post that was closely related to the symptoms I'm having was this:
http://www.peachparts.com/shopforum/showthread.php?t=48308&highlight=vibration+e420
But his vibration goes through the steering wheel more it sounds like. (and he never solved the problem
.)
-Keep me posted.