Before doing anything with new game files, always copy your Saves folder (found in AppData\LocalLow\Amistech\My Summer Car ).
This specific zip format is often used for manual backups of the game or for installing "Clean Saves" where the car is fully disassembled so you can start a fresh build without losing your career progress. How to use it: FГЎjl: My.Summer.Car.v2022.12.22.zip ...
If you're using this file to fix a broken car, make sure your version of MSCeditor is updated to read the 2022 save format. Are you trying to install this as a clean save, or Before doing anything with new game files, always