I'm glad someone mentioned this, all my cars have done this as they aged. I drive brand new cars as a part of my job and new S2000s do not do this. I do have a more aggressive setup on the car so it's not always fair to judge, but I'm thinking it's something that wears and changes as the car gots older. My thought is the suspension bushings are deflecting more when subjected to simultanious upward/rearward movement (like the kind you get when you hit irregular surfaces on the road under braking). This problem of 'pull" is not evident on a perfectly smooth surface so it's not tire pressure or brake distrubution. Any suspension guru's out there care to elaborate on my 'backyard' theory?

 

What you may be experiencing is caused by the ruts at intersections. Constant stopping of cars and trucks causes this. The force is pushing the pavement forward and out over time. The S2000 has wider tires than most cars, so would be more sensitive to the ruts.

 

This may sound stupid, but what about the reduced gyroscopic effect as the wheels slow in spin. I know motocycles wander all over the place when speed is slow.