As a game designer myself i can say that a really awesome feature would be the abilty to export the cars you designed as 3d models.
While this isn’t a core factor of the game and a feature probably not alot of people will use it would make so much easier for alot of game designers.
I am currently making a racing game and by far one of the hardest things to do is create costum 3d car models.
But making costum cars in automation is not only simple but also alot of fun!
If you are a gamedesigner, you know how hard work it is to export them as 3d models.
As it only benefits many different purposes than those that belong to the game itself, I would highly doubt the developers of Automation would put time into this at this point.
You dont need custom cars, just go out there and download some free car models on the internet. They are up for the grabbing. With minor tweaking you can make them custom yourself.