A few "Unicorn" cars and specific DLC/Car Pass vehicles still require their respective purchases or specific achievement milestones. Legitimate "Unlock" Methods
You must increase your collector score by owning other cars to reach higher tiers (Common to Legendary). Only then do the highest-end cars become "buyable". Rent for Free: Forza Motorsport 7 Unlock All Cars Cheat -UPD-
mode for no cost, though you won't earn credits or XP from these races. Credit Glitches & Trainers (External Methods) A few "Unicorn" cars and specific DLC/Car Pass
If you just want to drive a car immediately without buying it, you can any car in the game in Rent for Free: mode for no cost, though
You can now find the vast majority of cars—including previously "hard to find" and Forza Edition cars—directly in the "Buy Car" menu. Exception:
If you see a car is still "locked" in the menu, it is likely tied to your Car Collection Tier Car Collection Tiers: