After trying to visualize all the different arcs the rear suspension arms have to move in, during bump travel, it seems like there would be a tremendous amount of binding/twisting forces applied to the anchor points, if you replaced the original compliant bushings, with poly bushings. It would be great if there was a available spherical bushing that could be pressed into one the pivoting ends of all 6 control arms. Newman had the right idea, but it could surely be done for less than $700, I would think.