I never had clunking issues on my 2010 GT.... but the oem GT strut mounts don't allow for any camber adjustment..which drove me nuts. The steeda strut mounts are built like a tank, and allow +/- 1 deg of camber adjustment. ( that's +/- 1 deg of whatever you have to begin with). Mine was -1.1 deg on the pass side..and -1.4 deg on the driver's side. Once the steeda mounts were installed..they are now both set to -1.0 deg........ which is a good compromise between handling and tire wear for a typ street car ( esp with a staggered setup..where you can't rotate). The oem GT strut mounts and also the GT-500 mounts...are both one time use only devices. The latest version GT-500 is the C version..which clunks worse than their previous versions.
I wish I had installed the steeda mounts at the same time the Roush suspension was installed..... instead of having to do it all again..pita.