Herbert Wallerstein, former executive for 20th Century Fox, was robbed and beaten to death, and his body was placed in a car that was set ablaze, authorities said. Wallerstein, 59, was found Sunday in his burning car in Woodland Hills, coroner's spokesman Bill Gold said. An autopsy determined that he had been beaten to death, Gold said. Wallerstein had been in show business for more than 40 years. He left Fox in December, retiring as senior vice president in charge of feature films, Fox spokesman Jerry Greenberg said. Wallerstein was last seen alive Friday night at a supermarket near his Calabasas home.