Originally Posted by Riddler
http://www.bmwe34.net/e34main/mainte...r_arm.htm#Back
No, rubber has better damping characteristics and if you didn't want a little damping here why not use a steel bushing? Also rubber ages gracefully, I've read reports that urethane bushes tend to crumble into dust when they eventually pass their use-by date. Look at some old BMW posts by Jim Conforti for a more detailed examination of the topic.
Bill K. in Sydney, Australia