trouble is they need to compress to fit in, which they cant do when frozen. I had a trolly jack under the bush and jacked it up hoping it would go in at one stage. Little did i know, it just lifted the car up in the air, still didnt go in more than half way iirc.
Problem is (as i see it anyway) is the donut is not the same shape as the hole in the arm. The bush (basically) has parallel sides top to bottom. The hole in the arm has parallel sides to about half depth, at which point it tapers in by about 7 mill (at a guess) so, as you press the bush in its fairly easy until it gets half way in, but gets harder as it has to compress its width by a total of 14 mill(or whatever it is) to overcome the taper in order to seat fully home.
From Marks description, whats happening is the rubber is gripping/deforming in the tapered part of the hole and not compressing/sliding to the full depth. So when you release the clamp/pressure it forces itself partly out again, sometimes over a period of a couple days, sometimes, if you use silicon grease it squidges out quicker than you can get the clamp (or whatever method) back on again.
I cleaned off the silicon and re fitted, a couple of days later the car felt crap at the back. I checked and forced them in again. They are now in bar a couple of mill or so on the forward facing edge.
Thats how I see it anyway.
My original thread,
http://www.omegaowners.com/forum/YaBB.pl?num=1227822287/13