Look at this
thread . Some dude mentions that he replaced a mount and it improved things.
I replaced my front motor mount at around 20k when it was 4 years old. My engine flopped around enough within the frame to bend the heat shield on the aftermarket front pipe. I noticed no change in vibration with the new mount. IMHO a waste of $110.
Have you tryed adjusting the engine stablizer (top engine mount located between the cylinders)?