[wakespeak]

I did it piece by pieces to get a sense of the changes:

Stock: car fun on track but too much body roll and rear suspension compliance.
1) 1LE rear bar. Body roll dramatically reduced. Car more fun.
2) 1LE toe links. Noticeable reduction in rear end steering under power and in corners.
3) 1LE front bar. Cornering now essentially flat. Understeers at the track, particularly under power on corner exit.
4) 1LE rear shocks. Car used to float on the road a bit at highway speeds and bounced on the track. The new shocks mostly corrected this.
5) JPSS front radius arm bushings. Turn in crisper. Also vibration under hard braking eliminated.
6) 19" wheels. Better acceleration and grip. Front bar exaggerating understeer more. Corded a brand new set of MPSS in 2 track days.
7) 1LE front struts. Slightly stiffer than standard FE4 SS. Float reduced and better control at track. Changed camber at install to max at -2deg (kept toe at 0 deg). Front tire wear now normal at track. Car now a neutral handler at the track, just use the brakes or throttle to move the CG forward or back in corners. *Now annoyed with remaining lateral wiggle at track and turn in a bit lagging.*
8) CTS-V brake upgrade. Uh wow. I can now max my straight line speed and brake later. A LOT more confidence.
9) Pegasus solid cradle bushings + Z/28 rear upper control arm bushings. The car finally feels "done". It is subtle, but I had to change my turn-in timing just in street driving. There must have been a slight delay even in street driving as the car "took a set". Car just goes where you point it. Can't wait to get it out on track.

Next I will likely change to 3.91 gearing as I get bogged in 3rd occasionally.

Edit: track weekend at COTA. Wiggle gone. Rear end breaks progressively and predictably. Do the solid bushings!