In the screenshot below you can find the way I wanted to create a new car for my skin. But unfortunately I only can use a alternate skin of an existing one. Against all tutorials I found, the sim doesn´t create a new car in the menu. Also find attached a screenshot of my new skin folder. Cheers for the help
It's naming conflict some where it, quite often happens. A name has been used before some where, my usual cure is to use the underscore key instead of space, this usually cures it. You don't have to recreate it, just go to the setting folder for the particular car and edit the folder name and rcd file and reload the game so it reads the newly edited folder and rcd file names. Hope this is of help.