I install all these with the car weight bearing, then use a large c-clamp but really dont have to compress that much. I do use the IE urethane bushings so I don't worry about them getting trashed too soon. Also as done, head of bolt is down just in case someone puts a jack under it, bends it and makes it hard to remove. Agree, only place I have used urethane other than here is the inserts IE sells that can be added to the rear subframe bushings ( more so casue they are a PIA to replace).