alexchannell

I don't experience this at low speeds, but at 50+. I'm not loading the tires that much, maybe 70% of their ultimate traction. When I hitt little bumps (these are tiny, like undulations in the pavement) the car gives little swerves. It is a very uneasy and confidence robbing feeling. My NSX w/NSXR suspension did not have this traight, and it was there but not nearly as pronounced in my 1st gen MR2.
The car did have an alignment before I bought it and I don't know what specs they used.
The car is at 47k on the stock suspension, never tracked that I know of, stock wheels, with "ultra high performance all seasons" Pilot Sport A/S Plus

robinson

You may have an incorrect toe setting on the rear wheels. Put it back on the alignment rack and find out. Also, get under the car and make sure all the bolts are tight on sways & bushings.

twohoos

In terms of handling, S2000s have two Achilles heels: rear bump steer, and rear aero lift. At 50+ and high lateral g, you'd be getting some of both.

Definitely get a good alignment, and ask for a full 1/8in. of rear toe-in (1/16 per side). There are rear bump-steer kits available if that doesn't settle things down sufficiently.