After a high-flying 2004 season the most conspicuous drop in performance after Ferrari was BAR-Honda, who were banned from two races after scrutineers in San Marino discovered a hidden fuel compartment that allowed their cars to run underweight. They were beaten in the championship by Williams, whose engine partner BMW had announced they were leaving to join Sauber in June, and Toyota, who achieved 5 podium finishes and were only beaten to third in the championship because of Ferrari's 1–2 in Indianapolis.