My MY 2005 is stock with about 36k miles. Occasionally on a sweeping left turn the steering feels like it catches in one position. By catching I mean I feel some resistance to change when I try unwind from the turn. A slight push more and the steering responds as expected but it definitely wasn't totally smooth. I don't feel this on right turns or on quicker left turns were the steering doesn't rest in a position. I think it happens more frequently right after I start a drive. I think it started when the car had less than 10k miles.
I've had several different dealers check suspension and steering but they find nothing. I have also felt the effect after carefully adjusting tire pressure to 32 psi.

Any ideas out there?

 

I had a similar problem with my old car, a Renault Megane sport, it turned out to be a tracking rod!

 

Would the equivalent part in an S2000 also be called a tracking rod?

 

Yes.... I'm not saying that's def the cause but defiantly worth a look at.

 

What are your front toe settings?