Almost immediately the T43 design was replaced by the Mark III version of the "Formula Two" chassis. Maddock and the Coopers upgraded the existing design by switching the front suspension for an improved double wishbone suspension arrangement with coilover shock absorbers, in place of the older cars' transverse leaf spring design. New step-up gears in the transaxle allowed Maddock to lower the engine (now including Climax's stretched "FPF" in the works Formula One car), reducing the centre of gravity of the new Cooper T45 (Mark III) by mounting the dry-sump engine much lower. Maddock credited this particular innovation to Jack Brabham, who received the suggestion from his Australian friend, Ron Tauranac. Brabham and Cooper contributed other detail improvements, but Maddock left the fundamental chassis frame virtually unaltered from the T43. The T45 was immediately successful. In the hands of Maurice Trintignant, Rob Walker's new T45 won the very next World Championship round, the 1958 Monaco Grand Prix.