Anyone figured out how to keep the stock mirrors from vibrating?

Mine don't seem to vibrate? If it's brand new (2004), let the dealer take care of it under warranty, I say!

Yours don't vibrate at all?  I can't tell what kind of car is behind me if I'm going above 25-30

Nope, not at all. In fact, to change the mirror position, I have to practically reef on the whole stalk for it to move, and I don't consider myself a weakling! Same goes for the mirror swivel, it's pretty tight as well. Sounds like yours is too loose.