Rob is the husband of J.D.'s sister Peggy. He runs a car lot, and his business practices are often called into question, as is his devotion to Peggy. J.D., ever the opportunist, often approaches Rob when Rob is in a tough situation (such as when he is arrested for soliciting a prostitute), and promises him help, but only in exchange for a free car. J.D.'s schemes involving Rob almost always fall through in one way or another.
