The Ford Mustang refers to the 1968 automobile which is owned by the Bartowski family, originally owned by Stephen and Mary and now owned by Ellie and Devon as of "Chuck Versus the First Fight". We learn in that episode that some of Mary's fondness memories are of Ellie sitting between Stephen and Mary on long drives they went on when Ellie was very young. It is mentioned that the Mustang has blue colored seats which were specially ordered by Stephen.