Stewart is a one-time character, making his first and only appearance in "Happy Deals". Stewart was the bidder who purchased the toy racecourse that Grayson and Riley wanted for their own collection. During their mock race, the pair trick Stewart and take his toy racecourse, but pause when he begins to wail tears of sadness. The pair then stay back, and race their car with the boy.
He is voiced by American-Italian actor, Tony Almoda.