For PC players, these offline company saves are stored locally on the hard drive. You can find them by navigating to the following directory: %AppData%\Local\BusSimulator18\Saved\SaveGames Key Distinction
"A visual tour of Seaside Valley. This save showcases a custom fleet featuring unique liveries created with the Bus Simulator 18 Mod Kit . Explore new routes and custom-built buses that push the limits of what a transit company can look like. It’s not just a commute; it’s a gallery on wheels." Quick Technical Specs bus simulator 18 save game