Most modern trainers for Forza Horizon 4 are built to be version-independent, meaning they automatically detect your game build (including v1.477.175.0) and apply the necessary offsets.
Instantly set your credits to the maximum (e.g., 999,999,999) to buy any car in the Auto Show.
: This is widely considered the most stable option. The WeMod app offers specific trainers for both the Steam version and the Windows/Microsoft Store version .