Technical Director of several Formula One teams during the 1980s and 1990s. He died of a heart attack in Spain while supervising the testing of the abortive Honda F1 project. He attended Birmingham University to study Mechanical Engineering and graduated, with a doctorate, during the 1960s. After graduation Postlethwaite joined ICI as a research scientist, but a keen follower of motor sport he soon began to pursue a career as a race car engineer, joining March in 1970, then aged just 26. Postlethwaite worked on the fledgling company's Formula 2 and Formula 3 cars but was lured away to join the Hesketh Formula One team who were a March customer. Working to modify and improve the March chassis, Postlethwaite elevated the team into serious contention and the following year designed the team's car from scratch. Postlethwaite's 1974 Hesketh secured a number of podium positions and the following year the teams lead driver, James Hunt, took victory at the Dutch Grand Prix. By 1976 Hesketh could no longer afford to run the team and sold out. Postlethwaite went with his cars to the newly founded Wolf-Williams team, headed by Walter Wolf and Frank Williams, but the results were poor and the owners soon went their separate ways. Postlethwaite remained with Wolf, designing the team's 1977 challenger. Success was immediate with Jody Scheckter taking victory at the season's opening race. Two more wins and a number of podium results followed and Scheckter eventually finished second in the drivers' championship. Although Postlethwaite remained with the team until 1981 they were never to repeat their 1977 success, and after the team was sold he left to join Ferrari. At the time the Italian team were considered amongst the best engine builders in the sport, but amongst the worst car designers. Postlethwaite was selected personally by Enzo Ferrari to rectify this problem and by the following year everything was in place for success. The 1982 Ferrari took the constructors' title despite several serious setbacks, including the practice crash at Zolder which claimed the life of Gilles Villeneuve. Despite the loss of their inspirational Canadian driver, Ferrari repeated their 1982 success the following year, taking the constructors' title again. Postlethwaite remained with Ferrari until 1987, his cars taking numerous wins, but unable to compete with McLaren and Williams for title victory. Despite loyal service the designer was replaced by John Barnard and moved to Tyrrell, where he worked for four years. During his tenure as technical director Tyrrell's results improved noticeably, culminating in the 1990 season opener in Phoenix, where Jean Alesi was able to challenge Ayrton Senna's McLaren for victory. While at Tyrrell Postlethwaite employed Mike Gascoyne, who became his assistant and protege. In 1991 Postlethwaite was signed as technical director of the Sauber team who planned to enter Formula One in 1993. Taking Gascoyne with him, Postlethwaite relocated to Switzerland and designed the team's first car. Despite leaving Sauber before the start of 1993, and returning to Tyrrell, the designer's car went on to considerable success in the hands of JJ Lehto and Karl Wendlinger. Postlethwaite remained with Tyrrell until 1998 when the team was sold to become British American Racing. Although Tyrrell was a small, and largely uncompetitive team, the designer remained well respected within the sport and was hired as technical director of the Honda F1 project. Although Honda had not committed to race in Formula One the project produced an evaluation car, designed by Postlethwaite, and it was during testing of this car in Spain that he suffered a fatal heart attack.