Mine only lasted about 20,000 KILOMETERS before Ford had to replace them. No big deal, it was free and in for an oil change anyway. Why they made you pay is a mystery to me; it is a well known issue. Energy makes poly replacements for these bushes at about $24 for the full rear set.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP