but I only drive F1 cars .... is there an F1 mod for it ?
Like mention several time in this thread, there is a F1 car it's call Formula Reiza. And the formula Classic is an 1988 F1.
But i get the feeling what you are looking for is a full field of current F1 teams with F1 tracks.
GSC is mainly a StockCar V8 sim with real teams and tracks from 2010 (i think) championship, recently Reiza added 2 fantastic F1 cars and soon we should get a F3 that should fit the GSC track selection better, the only real F1 track we have atm is Interlagos (and Jerez even if not a current F1 track)
I was mainly looking for open-wheelers before trying GSC, the quality of the sim is so good that i couldn't resist buying it, and I really enjoy driving those V8 now and only regret i didn't bought it sooner.
Only you know what you really want, all we can tell you is that the quality of physics, tracks, ffb, textures of the whole GSC package is outstanding. The demo is there for you to try, i don't know if new F1 cars are included in the demo or the 1.7 patch but if you can upgrade the demo you should ugrade everything you can before launching the game, demo is only 30 minutes.
But again, if you're only looking for F1 cars and tracks then maybe this is not for you... your lost hehehe