Yeah, it looks as if Realtime did start in 1997(and won the championship with an ITR in 97, 98, 99, 00, 01, 02). They had two ITRs on the track May 23-26, 1997. The GSR they have listed for February 21-23, was their probably their older bodystyle GSR. So, if Realtime managed to get them on the track in May 1997, they had to take delivery of it in late 1996 or early 1997! I would say their cars are not included in the retail sale numbers. So, that is 2 more ITRs in 97 and 1 more in 98.

http://www.world-challenge.com/97/index.html

http://www.world-challenge.com/archives/

On another side note, the Realtime NSX is a pre-production prototype made in 1989