If you cannot find the AppData folder, ensure you have "Hidden items" checked in the View tab of Windows File Explorer.
This leads to a crucial distinction:
Here’s a detailed guide on saving your game in The Long Drive — including how the save system works, where save files are located, and how to manually back them up.
Generally, the game does not feature a robust auto-save system that triggers while you are driving down the highway. It relies on the player manually saving via the "Save and Exit" function. However, the game does save your stats and achievements to your profile, but your location, car damage, and inventory are tied to the manual save file.