Car Editions, create versions of each model.
Just like real-life companies, you can create a core model, and versions based on the core. Take Porsche 911 for example, you've got, the Carrera, Carrera S, Carrera cabriolet, and so on. Make automation game create a core model, then, you can create versions of the core, like supercharged engine, better transmission, or new grille!