^ Hey m8,
I just downloaded this game yesterday, as I'm a LFS freak!
What you have to do is go into D1 Grand Prix All Star 1.0 folder > 'Double Click' the rFactor folder, and then COPY all of those things into the rFactor directory so, C: > Program Files: > rFactor: > *here* and it will ask if you want to overwrite and just choose yes! then you'll be ready for action m8,
Hope this helps, I was getting quite frustrated myself, the 'readme' isn't very helpful in this section...