It's not much use now because its terribly outdated and the multiplayer function of it doesnt work anymore, it was only meant as a help for them while developing the multiplayer portion of the game.
I think that rFactor should have done a similar system to LFS where you can download the full version, but have limited access, and unlock it later, because there are a lot of people sitting on the fence and it would help convert the masses!
The fact that its so open to modding means thats never going to happen, but you can buy the full version and get a refund before 48 hours. Only thing is the default game is nowhere near as impressive as its already been made with mods and it will get a lot better in a few months. Within a year it'll hardely by recognisable as the same game so people trying the default game for the 48 hours then getting a refund will be missing out.