I was there around 7:00 PM, but didn't see any other NSXs. Someone told me they saw one other NSX -- a red one.
By this time (5 years of ownership) I am used to having a bunch of people gather around. I am also used to getting my picture taken while standing still or driving. But a new one happened Saturday: People calling their friends telling them to get on down because there was an NSX there!
I made a number of peoples' day by letting them sit in the driver's seat.
I was impressed by the wide cross-section of people there: all races, all classes and everyone having a wonderful time. I'll do it again next year and get there a lot earlier.