I understand where you are coming from, but disagree somewhat. I think bushing material is one of those things that a manufacturer designs more for comfort and mass consumer satisfaction with the fact in mind that the design will be giving up some performance. There's usually a trade off. With a part such as control arm bushings, rubber may isolate some of the suspension vibration but will allow the pivot point to shift slightly and thus result in less precise suspension. I do believe that the aftermarket UCAs all come with poly bushings most likely for performance rather than ride quality (a.k.a. "comfort"). With a part like a motor mount, you would definitely feel more vibrations with a poly mount but will also have more direct power transmission. This can be taken a step further with aluminum mounts and bushings, but that will surely transmit those vibrations to other things and most likely cause damage somewhere down the line. The squeaking is just another trade off that one has to weigh for themselves.
So Dick, I only have 9 posts but I do read the forum just about every day and know you have a lot of good info to offer. I also appreciate your feedback but didn't really get an answer to my question of, "Is there a poly replacement kit on the market?"
Thanks a lot