It would be a dream to have these cars, but I think, that will remain so
Download Blender and Gimp (both are free), start a modelling basic tutorial on YouTube (that is free too), and make your dream come true.
modelling a car is one thing, making the physics, sounds, and scripting it to work with assetto corsa are completely different things.
but if you can offer any of those parts, it would be way easier to form a project group. So have a go on either of them and then come back asking for helpmodelling a car is one thing, making the physics, sounds, and scripting it to work with assetto corsa are completely different things.