Complete specified tasks to unlock following areas.

Area	Task
Burnout Glacier	Complete Mission 9 In Adventure Mode.
Crankshaft Bay	Complete Mission 6 In Adventure Mode.
Crankshaft Docks	Complete Challenge 8 In Challenge Mode.
Glacier Race	Complete Challenge 11 In Challenge Mode.
Sewer Pipe Arena	Complete Challenge 5 In Challenge Mode.
Treadwell Plaza	Complete Challenge 14 In Challenge Mode.
Turbine Sands	Complete Mission 3 In Adventure Mode.
Underworld	Complete Mission 12 In Adventure Mode.
Underworld Arena	Complete Challenge 17 In Challenge Mode.
Underworld Race	Complete Challenge 2 In Challenge Mode.