The Stairliner Commander is a 1954 vehicle manufactured by Studebaker. It was Grampa Simpson's car.
When Bart was sad because Abe couldn't play with him and his toy cars, Grampa decided to show Bart his old car. According to him, he bought the car brand new and forgot it inside the garage. When Bart asked if he could sit on the car, Abe surprised him saying that he could actualy drive it. Two years later, the car has some damaged and rusted parts.
- It's unknown if Grampa actually owned this vehicle, as both times it appeared are flashbacks that are considered as non canon.