If understand you the plugs where in there for 17 yrs ?
My first year S2000 had it's plugs replaced after a year or two when Honda issued a TSB. Those plugs are still in the car, and working fine. They do have only 45K km on them however. The NSX is also on the original plugs as far as I know. Got it with 9K miles and now has just under 19K. :encouragement: