In Leonard's first year he took home two podiums,[1] consisting of a win, and third place position, both at the Nürburgring GP circuit in Germany.

In 2013 Leonard moved up to the top of the Caterham ladder (R300 Superlight Championship), whilst being coached by the 2012 R300 Champion, Paul Wilson.

[5] In 2016 Leonard entered the Dubai 24 Hour, alongside his teammates Laurens Vanthoor, Michael Meadows and Alain Ferté.

Leonard also competed in the 24 Hours Nürburgring, with teammates Robin Frijns, Frederic Vervische and Edward Sandstrome, finishing eighth overall.

Leonard also competed in the Blancpain Endurance Pro Cup, taking a second place finish in the Barcelona round with teammates Robin Frijns and Jake Dennis.