If this is a mod file you've downloaded, follow these steps to get it working in-game:
Right-click and "Extract All" to see the internal files. File: BeamNG.Drive.v0.25.5.zip ...
Open BeamNG.drive, go to the Repository , and click Open Mod Folder . Keep it Zipped: Do not extract the ZIP file. If this is a mod file you've downloaded,
Ensure there is a folder named vehicles or levels at the top level. go to the Repository