their rivalry pushed the development of the car far ahead of the other teams as they tried to out-do each other (although theirs was a very public rivalry, both actually worked well together in testing and Prost believed neither held back any information). Although Senna won six races to Prost's four and usually finished ahead of the Frenchman in the races, accidents and car breakages meant that he had four fewer points-scoring finishes and finished 16 points behind his French rival in the championship. Senna and Prost's combined points total meant McLaren easily won their second straight Constructors' Championship. A version that had a transversely-mounted gearbox made its debut at the British Grand Prix, with Prost taking victory however Senna went off at Becketts while struggling with the gearbox in his car. Like 1988, the Drivers' Championship was a two-horse race between defending champion Senna and dual champion Prost. The championship was settled at the penultimate race in Japan. After dominating qualifying (with Senna predictably on pole), the two McLarens were evenly matched in the race and simply drove away from the rest of the field until their fateful collision at the chicane on lap 46. Prost was out on the spot while Senna was able to restart and after pitting for a new nose section, re-took the lead from the Benetton-Ford of Alessandro Nannini and went on to win the race. Ultimately, however, he was disqualified post-race for receiving a push start and missing the chicane after restarting which gave Prost his 3rd World Championship. 1989 was McLaren's fourth Constructors' Championship of the 1980s following on from , and , making the team the equal leading constructor of the decade with Williams who won in , , and . It was also Honda's fourth consecutive Constructors' Championship as an engine manufacturer, and McLaren's fifth Championship overall having won their first in . 1990: MP4/5B Prost went on to move to Ferrari for the 1990 season, as announced during the midseason of the previous year, taking designer Steve Nichols with him. The Frenchman was unhappy because he believed that McLaren and Honda were favouring Senna. As a result, Ferrari and McLaren swapped car numbers, giving Prost and teammate Nigel Mansell the numbers 1 and 2, and giving Senna and Gerhard Berger, who had swapped with Prost at Ferrari, the numbers 27 and 28. For the 1990 version of the car,