This mod is at the same level as the historicX mod for me.
I play other (pay as you go) racing sims and let me tell you, after I got a hold of this mod I have gone back to rfactor full time.
My favorite, so far, is the Ferrari F430. First time I enjoyed driving a Ferrari in a sim. Not the easiest car to drive. However the Porsche is harder to drive and thus it is next in my list of cars to tame.
My hat off to all involved.