There is a little feature that could be useful.
1) Open wrs.ini and add the following lines ( or just the second if the "edit" section already exists )
[edit]
groove=1
2) Drive several laps in testing mode on a track to create the groove ( it's possible to use groove_multiplier (http://forum.piboso.com/index.php?topic=7.msg10#msg10) to generate it faster )
3) Press left ctrl + g: a file named temp.grv will be saved in the World Racing Series installation folder
4) Rename temp.grv to track_id.grv ( for example: victoria.grv ) and move it to the proper track folder, with the matching TRP file
5) World Racing Series should automatically read this grv file at track load time