depending on how much you drive the car, they will probably wear out fast since there is no isolator between the two, and I second what CP said, you will definitely notice an increase in noise (probably will be able to hear the rear end gears and wheel bearings clearly) after going to a solid bushing. I had delrin bushings in another car I had and the rear end noise was very noticeable but that was my commuter car too, so on a weekend only type car it may not be that big of a deal.