sentences:  Postlethwaite kept the oversized rear wing of the 126C2B, and over the season, Frenchmen Patrick Tambay and René Arnoux scored four wins between them and were both in contention for the world championship throughout 1983, but late unreliability cost them both.However, Ferrari took the constructors' title for the second year in a row.In the season McLaren introduced their extremely successful MP4/2 car, which was far more effective than the 126C4 and dominated the year.