GTP has its own track directories (one for day and one for night
courses).
You can simply copy any existing N2K3 track into the appropriate GTP
track folder and then do two additional steps.
(i) Copy the four fast.gtx.xxx files from one of the GTP tracks into
the new track folder.
(ii) Open the track.ini file in one of the GTP track folders and find
the sections pertaining to GTP/GTN AI and GTP/GTN and copy them into
the track.ini file in the new track folder.
For optimal results, browse over to the GTP web site at
http://www.redlinedevelopments.com/index.php and find the GTP Setups
section. There are downloadable setup files and track.ini files for a
great many of the road course tracks already done for you.
Installation issues are covered there as well.
HTH,
--
Darryl