I haven't read the manga, but I happen to know that some cars aren't shown in the 1st season. For example, Supra MK5 ( despite being shown in the poster), Aston Martin Vantage and Lotus Emira.
But for future seasons of MF Ghost, will the show go with a further approach with the choices of cars? Meaning, cars that are not from the mangas and new drivers will come to life on the show. E.g. Bugatti, Koenigsegg, Hyundai, Mclaren, etc. (P.S. Even if so, I hope that the show doesn't make Kanata beat them all in his mere GT86, and more probably, switch to another car if that were to happen soon of this possible approach)