How do I put my own brand of car in this game? What is the software I need to create the content? I want to put my own cars in this game, and I have an Automation engine converter that works (just tried it, the drag car is a million times faster now).
It takes several hundred hours of work to make a good mod for this game. It's not as simple as Automation, which is designed for that.
Then start with doing that to an existing vehicle. The only tool you will need for that is a text editor.