Thanks for the replies. Just wanted to give a quick update on the new motor mounts. Finished the job on 2/19. It went well. The new mounts were significantly taller than the old ones. The driver's side mount looked very compressed(collapsed?). It was maybe 1/2" to 3/4" shorter than the new one. The right side was about 1/2" shorter. I used the "raise the engine from the oil pan" technique with blocks of wood which made me nervous, but it worked fine. Overall, not a difficult job if everything lines up and comes apart right, but I did swear a few times.
Results? Very nice. Vibrations at idle nearly gone. It also fixed a problem I did not know I had. At engine start-up and shutdown there used to be a rocking of the entire car. This is totally gone. I think I am getting close to that "silky smooth" engine operation. Cap and rotor replacement happens this weekend.
The 300E is growing on me. Perfect car? No. But what other choice is there?