Hi Tom & Eric.
Eric - The mod I was trying to open is the 1991 mod from gp4 database. It's named 1991.cuh but WinRAR lists it as a CSM file.
Tom - Is this what you wanted?
09:23:19: ### Logging Started: Gp4 Library 0.8.108 on 12 Apr 2016
09:23:19: ### C:\Program Files\ZaZ GP4 Tools\DLL\gp4lib.exe
09:23:19: CSMPath = C:\Program Files\ZaZ GP4 Tools\
09:23:19: CarsetPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\
09:23:19: BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:19: Gp4Path = C:\GP4\Grand Prix 4\
09:23:19: Gp4Exe = C:\GP4\Grand Prix 4\GP4.exe
09:23:19: Swap BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:19: Patch BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:19: Wad BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\CSMAddToWad\
09:23:36: ### Logging Started: Gp4 Library 0.8.108 on 12 Apr 2016
09:23:36: ### C:\Program Files\ZaZ GP4 Tools\DLL\gp4lib.exe
09:23:36: CSMPath = C:\Program Files\ZaZ GP4 Tools\
09:23:36: CarsetPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\
09:23:36: BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:36: Gp4Path = C:\GP4\Grand Prix 4\
09:23:36: Gp4Exe = C:\GP4\Grand Prix 4\GP4.exe
09:23:36: Swap BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:36: Patch BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:23:36: Wad BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\CSMAddToWad\
09:26:26: ### Logging Started: Gp4 Library 0.8.108 on 12 Apr 2016
09:26:26: ### C:\Program Files\ZaZ GP4 Tools\DLL\gp4lib.exe
09:26:26: CSMPath = C:\Program Files\ZaZ GP4 Tools\
09:26:26: CarsetPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\
09:26:26: BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:26:26: Gp4Path = C:\GP4\Grand Prix 4\
09:26:26: Gp4Exe = C:\GP4\Grand Prix 4\GP4.exe
09:26:26: Swap BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:26:26: Patch BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\
09:26:26: Wad BackupPath = C:\GP4\Grand Prix 4\Gpsaves\Carsets\backup\CSMAddToWad\