Diamond Motors is an auto shop in Little Italy, Empire Bay. It was originally designed so that Vito Scaletta could buy cars from the shop, but the idea was scrapped from the game and it's no longer accessible to the player. However, its interior can still be seen in the Carcyclopedia.
- In the last cutscene of Balls and Beans, Joe Barbaro buys a brand new Smith Custom 200 in red and white.
- In the opening cutscene of The Betrayal of Jimmy, Jimmy smashes several cars there with a baseball bat.
- In the mission Jefferson Provincial Theft in Jimmy's Vendetta, you steal a Jefferson Provincial parked in the back of the building.
- Diamond Motors commercials can sometimes be heard on all three of Empire Bay's radio stations.