How do you mod a car in gta using in steam?

To mod a car in GTA using Steam, first ensure you have a modding tool like OpenIV or a specific mod manager installed. Download the car mod files from a trusted source, then use OpenIV to replace the car model files in the GTA directory. Always back up your original files before replacing them, and follow any specific installation instructions provided with the mod. Finally, launch GTA through Steam, and your new car should be available in the game.