Won Gold on all Playlist 2 Challenges in Co-op Mode.
Playlist 2 has a total of 3 challenges:

(1) LA Drift Battle

Gold Medal Requirement: 40,000 PTS (solo) - 40,000 PTS (co-op)
Preferable Car/s: Dodge Daytona 1969
Preferable Mods: Double Acceleration - Drift Boost - Any

(2) LA Air Support

Gold Medal Requirement: 30,000 PTS (solo) - 30,000 PTS (co-op)
Preferable Mods: Double Health - Explosive Ammo - Any

(3) Rio Rampage

Gold Medal Requirement: 5000 PTS (solo) - 5000 PTS (co-op)
Preferable Mods: Double Health - Double Armor - Any