You beat the target time in a Vehicle Challenge.

You returned Callahan's call and became his poster boy for the World Series of Racing.

Complete the Story Mode by recovering the Iron Fist of Arkus and defeating Kaos on any difficulty

Complete Chapter 14

Complete Chapter 12

Chapter 11 - Damage Drill-X by throwing a pipe at him

Chapter 5 - Destroy 7 snowmen

Complete 1 Heroic Challenge

Successfully land on carrier at mission’s end

Kill 25 enemies using thermal or night vision goggles

Complete Chapter 9

Rescue the friendly ("From Out Of Nowhere")

Take a successful shot from a distance of 1 km or greater