The tool must reverse-engineer the binary format used by the game. It reads the bytes and maps them to specific variables identified through reverse engineering (trial and error by the tool developer).
Before making any changes, you must find your save data. For the Windows Steam version, the default path is: %USERPROFILE%\AppData\LocalLow\Red Dot Games\Car Mechanic Simulator 2021\Save
If you cannot find a specific "CMS 2021" editor, search for or "Madden 21 Franchise Tool" – these are the same utility rebranded.
Simming 20 seasons to see a regen develop takes 40 hours. Using the editor, you can jump to year 2040 in ten minutes to test a tactical theory.
Steam automatically backs up save files to the Cloud. If you edit a local file, Steam may detect a version mismatch. When launching the game, Steam might prompt to "Download from Cloud" (overwriting your edited save) or "Upload to Cloud" (keeping your edited save). Choosing the wrong option can undo your work.
: By using search functions (Ctrl + F), players find and change specific numerical strings. Common Strings : PlayerMoney to increase credits.
Understanding how to without a tool. Comparing different modding tools available on Nexus Mods.