I started making a McLaren P1 with SolidWorks, with the ambition of writing a free PDF tutorial in parallel, to allow those who are interested to also get started and learn 2-3 tricks :)
This is not my first car or my first tutorial, I have already modeled the complicated shapes of this beautiful piece so as not to go blind. The tutorial would come out on my site as I went along: http://www.imagine-cad.com/free-tutorial-mclaren-solidworks/
I will not proceed in the most intuitive way possible, namely to model the largest and then detail, but for an educational interest I will divide the modeling into chapters dealing with an area of the car...
Here is the subject of the first chapter, the roof:
For the Cox challenge, no, it is not necessary to participate in all 3 challenges. We can very well make just one.
The idea of the first one is simply to collect as much documentation as possible, files, etc. in order to have a common basis to then model the Cox. If we don't gather enough documentation, I'm not sure we'll launch the other 2.... to be seen...
The first one ends on the 22nd yes, but just to make the refs ... Modelling will then be the subject of a new challenge.