Well, judging by the picture, I've noticed a few things.
1. The length of the rod. By the looks of it, it does not seem as long as the MM rod. MM panhard bar bracketry has a pick up point that goes down from the rear subframe rail, and all the way down. KB looks like it swings a little to the side for whatever reason (probably exhaust clearance). Shorter bar will cause the rear to swing more from side to side as it goes through travel, and cause more rear steer. I would really like to see one of those installed to clear that up.
2. Install points. Looks like the chassis end bracketry is setup to be welded or bolt to unibody rather than the subframe rail. Now, I don't know if you are aware of this, but mustangs have a fairly thin and flexable unibody structure, which is why we experience so much flex under cornering. Bolting something that's suppose to keep the rear end straight to the unibody, not such a good idea in my opinion. You could end up sheering metal.
3. The rear roll center. When you build a suspension package you have to make sure that roll centers are with in range of each other. For example, MM likes high roll centers, GR prefers to build suspension wiht low roll centers. I don't know much about what kind of roll center KB uses for their setup, so I can't comment on that, and how it would work with other front end systems. What I can comment on is that roll center adjustment is limited to only two settings, unlike MM which is infinate with in a certain range.
Something to think about.
