a standard spark plug should last 10-20K KM...those better/performance type should last 30-50KM....
Spark plug is wear and tear part...
Also life span of spark plug depend on your engine condition...if your engine makan engine oil / wrong tuning then your spark plug will wear out faster.
The other night, during TT, some of us mooted the idea of another Skyline gathering. If you remember, last year we had the event sometime in June and, personally, I thought, despite the lack of activities...
we have seen the V10 concept lexus pictures, which everyone assumed was the SUPRA, but this pictures are closer to the earlier "aston" styling concept pictures that appeared from japan.