The trick F1 cars that ended McLaren's post-Senna slump

In just three years at the start of the 1990s McLaren went from winning its fourth Formula 1 championship in a row in 1991 to failing to win a race in its first year without Ayrton Senna in 1994. The tough times continued until 1997, when the MP4/12 made it a winner again. Jake Boxall-Legge and Giorgio Piola visited McLaren's Woking base to take a closer look at the '97 car, the title-winning MP4-13 that followed in 1998, and they explain the brake trick both cars had that was ultimately banned.