Just to add an info after long research and search: Although at least the U.S. models of 1998 have an OBD II interface there is none in the german versions of the car (maybe also in other european countries but I don't know) - not even an OBD I. It seems that they were waiting here for the european OBD standards that came in 2001 - so I guess at least the german NSX models from this year on (or maybe a bit before) are OBD II compliant.
