DOES THE HDK SUSPENSION K-MEMBER HANDLE BETTER THAN A T-BAR SUSPENSION?

The article Blu posted makes it appear that there is a “J” bar welded to the inner fender in about the same area. And looks like there is a fair amount of plating that was added to shock mount area, too?

Now that doesn’t mean the car you saw didn’t just have the Monte Carlo bar kit added and the rest of it ignored. But the initial XV design appears to be more than just bolted to the inner fenders.

I still kind of wonder if a tie bar of some type between the shock towers on your car would make a difference. No idea how you could tell though.
Have you pondered the various origins and the paths forces take from the tire patch all the way into the chassis, and almost anything to shorten or stabilize that path makes for a more efficient and likely stiffer design.
Meaning, attaching to the top of the fenders, no matter what plating/bracing is added, is a bit off the mark IMO.