 Complete the following phrase:  The last year of the 2.5 litre formula produced repeat victories for Jack Brabham and Cooper, and saw Lotus, Porsche, and BRM campaigning rear-engined cars. Lance Reventlows Scarabs, like the Aston Martins, were front-engined and outclassed. Stirling Moss Rob Walker Lotus gave Colin Chapman his first Grand Prix win at 