Volkswagen of America Picks New Ad Agency: Arnold Fortuna Lawner & Cabot of Boston is the winner. The firm creates advertising for Titleist golf balls, McDonald's franchise groups and Nynex calling cards and pay phone service. The auto maker declined to say how much it spends on advertising, but the amount has been estimated at $110 million. The agency and its predecessor shops have also created advertising for the Oldsmobile and Subaru dealer associations in New England. Auburn Hills, Mich.-based Volkswagen of America Inc. put its account up for review in December after 16 months with the Berlin Cameron Doyle agency.