You can unlock this from traveling around the world map. Keep on playing the game, or just drive in between levels for it to pop.
As you drive around the map, you accumulate in-game milage. Onces it reaches 2km, there you go.
If you need to know how far 1km is, look at the top-right corner of the map. It shows you distance in meters. Just know: 1000 m = 1km
The game does show you your travel distance between levels on other platforms, but not here on the xbox version due to some added benefits.