The legitimate version of the game is available on Steam . If you are looking for the "full piece" (the complete experience), it is best to get it there to ensure you have the latest updates and working multiplayer.
In many online contexts, the term "piece" (or "masterpiece") is used by players to describe a game they find exceptionally well-made or enjoyable despite its indie or "low-poly" aesthetic. Overview of Motor Town: Behind The Wheel Open-world driving and logistics simulator.
If you have encountered a link specifically named Motor-town.rar on a third-party site or forum:
The game supports online play where players can work together in the same world. Safety Note on .rar files