I am curious about where is this process up to. There is a Beta product, which is available to those who sign up to the full product price - as it is now. That product is an apparently unfinished racing sim, with shortcomings, unfinished bits and some documentation. One has to pay the final(?) product price to play with the unfinished Beta.
Documention as it is deals with graphics and getting a car into the game. Physics is not described.
RF1 had physics which did not produce realistic tyre, and so, car behaviour, for the standard in-game cars. The documentation was so limited that many of us spent several years of spare time reverse engineering the physics to produce something that was arguably close to realistic. That will not be acceptable this time around. This new version may become so focussed on appearance that behaviour becomes unimportant, but if not, rF2 faces important competition.
I was impressed that Ben Collins (Stig, for some of us), in the CARS forum, described the dance that was the actuality of driving a car at speed. RF2 has to deliver that out of the box or it has lost it's way with the physics.
Where are you up to with that?