Options: 

F1 - Freeze AI

Notice: 

Don't activate cheat in main menu of the game if you do the game will crash because of anticheats, Start game first then open the trainer, Then continue game and once you start driving your car activate the cheat.

• Forza Horizon 3: Save Game (500 cars in garage) [2018-Oct-08]
• Forza Horizon 3: Trainer +8 v1.0.119.1002 {FutureX} [2018-Jul-27]