After testing for both RC Motorsport and Pons Racing, Leo signed with the latter to contest the 2009 season, alongside Spaniard Marcos Martínez.

[4] In May 2010, Leo made his debut in the new Auto GP championship at Imola, replacing Adrian Zaugg at the Trident Racing team.

[10] For 2011, Leo raced in the FIA GT3 European Championship with AF Corse, sharing a Ferrari 458 with fellow Italian driver Francesco Castellacci.

[11] The duo won the drivers' title at the final round of the season in Zandvoort, finishing nine points clear of the Graff Racing entry of Mike Parisy.

[12] Leo made his GP2 Series début at the final round of the 2010 season in Abu Dhabi, replacing Edoardo Piscopo at the Trident Racing team.