Head to Grand Prix, choose McLaren (the orange car) and Fernando Alonso.
Select Singapore as your track.
In the race settings, you can change a few to make things easier/quicker:
> Weather: Clear
> Race Length: 3 Laps
> Rules and Flags: Off
> AI Difficulty: 0 (Very Easy)
Complete the race and if you finish in the Top 3, this will unlock.