Yo. I am the guy that Ace has mentioned. My motor mounts are like jelly. They are in pretty good shape as far as not being cracked or anything but they have just gotten soft. I bought some window seal with contains polyurethane and made a test sample and i am waiting to it to harden and then i am gonna beat the sh!t outa it to see how it will hold up. Hopefully it will do the trick of just stiffening my stock mounts (and tranny mount) which are still strong but lack stiffness. Also, when you do the hand test, put your body weight into shaking the motor, you will know right away if they are bad. I am gonna try different ideas when i reinforce them such as putting some hard rubber in there somewhere then sealing it all up with the urethane. Anyways, i am disappointed with the motor mounts nissan gave the 240, could have been much better. Hope this helps everyone, since i feel i am the king of crappy motors
-John