I remember reading something Sam Strano said a long time ago about steeda spherical bushing mounted atop the differential with a stock or polyurethane UCA yielding a good result without too much NVH.
This is the part
http://www.steeda.com/store/steeda-spherical-bearing-for-2005-and-up-ford-mustang.html
This is the part
http://www.steeda.com/store/steeda-spherical-bearing-for-2005-and-up-ford-mustang.html