No, it's the same. But I noticed before that you were not typing roms\daytona2.zip, but daytona2.zip. The error you got indicates that the game didn't load the ROMs. Supermodel will not even attempt to set the video mode before the ROMs are loaded, so double check what you're doing.
If "supermodel roms\daytona2.zip" works, then "supermodel -fullscreen roms\daytona2.zip" must work as well.
Email me at supermodel.emu at gmail dot com for further discussion. I'll get back to you in a few hours.