A 100% save file unlocks base-game content. If the save file was created by a user who owns DLC vehicles, those specific cars will remain locked to you unless you own the respective DLC packs.
The game stores its progress data in the hidden AppData folder on your Windows boot drive. Press Windows Key + R , type %localappdata% , and press Enter. From there, navigate through the following folders: ...\Local\Boston\Saved\SaveGames 2. Backup Your Original Files police simulator patrol officers save game 100 updated