I just installed the MM plates on my Eibach pro street S coil overs and it fixed the clunking problem. The MM kit I got is this one. Maximum Motorsports Mustang Caster/Camber Plates MM5CC-6 (11-14 GT, V6, BOSS) - Free Shipping
It says it will NOT work for the R1,R2 setup. But it does fix the noises up front.
2012 Grabber blue, Auto, Eibach pro street S coilovers, MM caster/camber plates, Borla ATAK cat back, off road X pipe, A.E.M CAI, SCT-x4 Mike Roush tune,SR LCA's, BMR Relocation brackets, J&M Pan hard bar, UPR Catch can, SVE 15x10's, Mickey T's 275-60-15.