Mateo is Mato's husband and Cruz Ramirez's cousin.
At one point before the events of Cars on the Road, Mateo and Mato met and got engaged to be wed.
Mateo anxiously awaited his bride, Mato, at the alter during his wedding. He watched in horror as she and her brother, Mater, began a series of competitions to prove who was better. This string of competitions caused the wedding officiant to leave, despite Mateo trying to get him to stay. Mateo confronted Mato, worried that this meant their wedding was off, until his cousin Cruz revealed that she had become a licensed wedding officiant during her off season from the Piston Cup. Mateo and Mato were married by Cruz, and after listening to a speech by Mater, the two raced to the wedding cake.
Mateo and Mato had their honeymoon at the World's Largest Tire Maze, where they both got stuck.