S04E17: The Trotting Horse

Granny asks Jethro to give her driving lessons. After the first lesson he quits & Mr Drysdale talks Jed into buying a trotter. The Clampetts just want the horse to take Granny to town when she wants to go,instead of waiting for Jethro to drive her. When a man arrives with the horse, he has the racing buggy with him. The Clampetts think it's a normal buggy without any sides or roof.