Contrary to what another poster wrote, when Jim Bob leaves his carved duck on the chair and it's found later on the car seat, Muffin actually picks it up from the chair and takes it in the car with her. You can see her holding it outside.
When Jim Bob sneaks out to hide in John Boy's car he leaves the carved duck on the chair, and then at the end it is found by his father in the back of John Boy's car.