Specialized sites offer RAR downloads of detailed 3D shapes, such as the Bugatti Type 57 , which are used for VR/AR visualization or 3D printing.
Depending on where you find the link, the file likely contains one of the following:
WinRAR vulnerability exploited by two different groups - Malwarebytes
Enthusiast clubs sometimes provide digitized replacement parts catalogues in PDF or compressed formats to help owners identify components for rare engines. Safety and Security Considerations