Ah cool, I was in the black gt parked right across from you guys.
I've only been to a few eurosundays, but they were either in Roseville or the pavilions on fair oaks.
This is how i did it:
http://www.mustang6g.com/forums/showpost.php?p=1706976&postcount=3
I needed a wobble extension to get mine, but I did the same install with my friend who has the steeda subframe alignment kit. His was a straight shot, no wobble needed.
Could it be drive line slop? I have less slop after those mods, but mine is louder now if i screw up a shift.. The only other clunking I had was from the front sway bar. The ford performance bar does not have stops, so it can shift from side to side when the steering is close to full lock. Mine...