While a single "official" save editor does not exist, several reputable third-party tools allow you to modify currency (Credits) and experience points (XP) to unlock all game content.
Always copy your original savegame folder to a safe place before overwriting it with a "full" version. project cars 3 save editor full
The developers (Slightly Mad Studios) encrypted these save files. You cannot simply open them in Notepad to change numbers. A dedicated tool or a hex editor with checksum correction is required. Features of a Full Save Editor While a single "official" save editor does not