I have a 87 325is. It never comes out of the garage except for the weekends and has about 170k on many of the original rubber bushings. As soon as our baby is here and i find a house with a two or three car garage, i would like to start going to track events. Any thoughts on solid, delrin, Urethane ,rubber, etc. would be helpful as i am going to go through the car and replace all/most.