The S2000 does not have a speed limiter.

6th gear redlines at 167mph if your speedometer is accurate. I have video taped a run up to an indicated 175mph but the tires were a little larger than stock.

 

We have a great stretch of road here in norther Cali. Interstate 280 from silicon valley to San Fran is scenic, curvy with big sweepers both left and right, 4-5 lanes each way, and other than peak commute times, relatively open. Traffic tends to move fast on I-280, with large clumps (8-10 cars) travelling in the 85-90 mph range. In early morning and mid-day jaunts, I routinely cruise this stretch at 115+ with the top down. I've played "tag" with a Nissan 300ZX Twin Turbo on this stretch for about 20 miles in very thin traffic. I would let him catch up, and just as he was closing, I'd wind it out and take off. I'd say our average speed was about 120 mph for the sequence, with several segments in the 135mph+ range. Top down in my case, of course. Nothing in the least bit scary about it, and no where near as noisy at speed as my recently retired (for the S2k) '99 Miata.