Well, I have the car dropped 2 inches in the front ( not my request see the coil spring thread ) polyurathane bushings all around and 265/50 up front and 295/50 on the rear.
The most noticable were the polyurathane bushings and lowered springs (did them at the same time) Wow, took the car on the off ramp and felt confident I was not going to be eating bark after it. And I was pushing it to just to see.
The next noticable improvement was the bigger tires, the car just hugs the ground. Makes sense, more surface area touching the street.
The bars are last in my opinion but are cheaper to do than the other mods so they usually get more attention.
But if your like me trying to hunt down scared imports on the road, do the bushing and springs. They look so surprised to see grandpas buick actually stay on them and then pass them asap after exiting the ramp.
You do need lowering springs to get a better skidpad g. New porsche 911 GT 2 is 1.02 g, super.
I have photos if you want to check out my cars ride height,
mike@spoolinup.com
It's those darn AWD talons/eclipses that are really hard to keep up with. I have one, wow, even better than in my buddies vette.