I created a thread for this game 2 days ago but turned into stories of failed marriages, so here it goes again.

Rfactor is a goddamn racing sim. It's by far the closes you will get to Gran Turismo on pc. It has a HUUUGE modding community, it can run on DX7,8 or 9, so even a netbook will play it, it's developer ISI is as standalone as developers can be and im sure it will accept if GOG made an offer.