Simply drag and drop the .7z file directly into the Content Manager window. It will recognize the car and allow you to install it with one click.
Search the Assetto Corsa Downloads for skin packs that add real-world liveries from the 1990s STW season. bmw_320i_stw.7z
Since this specific car has many versions (from creators like Patrik Marek or various "Touring Car" packs), you might find better textures or physics updates on community hubs: Simply drag and drop the
