DuPont Co, the third-largest U.S. chemical maker, plans to make corn-based plastics for automobiles and electronics starting next year to expand products produced from renewable resources. DuPont's Sorona thermoplastic and Hytrel thermoplastic elastomer will be available starting in mid-2007, Cathy Branciaroli, spokeswoman for Wilmington, Delaware-based DuPont, said. Uses include electronic connectors and plastic car parts, tubing and hoses, she said.