Use a tool like WinRAR or 7-Zip to extract the files.
Check for the latest MSCLoader releases and built-in bug report forms. Steam Community: Guides on installing mod loaders .
For further help, you can use the following official and community hubs: The primary source for My Summer Car Mods .
Below is a report on how to handle this file and the standard requirements for reporting issues with such mods to developers.