Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Premier Professional (5 points): Earn enough points playing the Championship to unlock the Premier Professional League.
Premier Expert (10 points): Earn enough points playing the Championship to unlock the Premier Expert League.
Premier Champion (20 points): Finish first in the Premier Final rally when playing the Championship.
Modified Amateur (5 points): Earn enough points playing the Championship to unlock the Modified Amateur League.
Modified Professional (10 points): Earn enough points playing the Championship to unlock the Modified Professional League.
Modified Expert (20 points): Earn enough points playing the Championship to unlock the Modified Expert League.
Modified Champion (30 points): Finish first in the Modified Final rally when playing the Championship.
Masters Amateur (10 points): Earn enough points playing the Championship to unlock the Masters Amateur League.
Masters Professional (20 points): Earn enough points playing the Championship to unlock the Masters Professional League.
Masters Expert (30 points): Earn enough points playing the Championship to unlock the Masters Expert League.
Masters Champion (40 points): Finish first in the Masters Final rally when playing the Championship.
Grand Slam (50 points): Finish first in every rally in the Championship.
Perfect Score (100 points): Finish first in every race in all rallies in the Championship.
Car Collector (20 points): Earn enough points in the Championship to unlock all the cars.
Livery Collector (20 points): Drive 50 miles in the first 6 cars in every championship. Single player modes only.
Safari Expert (10 points): Finish first on each of the Safari tracks in any single player game mode.
Lakeside Expert (10 points): Finish first on the Lakeside 1 track in any single player game mode.
Arctic Expert (10 points): Finish first on each of the Arctic tracks in any single player game mode.
Alpine Expert (10 points): Finish first on each of the Alpine tracks in any single player game mode.
Canyon Expert (10 points): Finish first on each of the Canyon tracks in any single player game mode.
Tropical Expert (10 points): Finish first on each of the Tropical tracks in any single player game mode.
Tourist (10 points): Drive a total of 300 miles (480 km) in any single player game mode.
Trekker (20 points): Drive a total of 500 miles (800 km) in any single player game mode.
Explorer (30 points): Drive a total of 1000 miles (1600 km) in any single player game mode.
Off-Road Expert (10 points): Win a Championship rally using the Off-Road setup.
Road Expert (10 points): Win a Championship rally using the Road set-up.
Manual Expert (10 points): Win a Championship rally using manual transmission.
Safari Time Attack (20 points): In Time Attack mode beat the target times for all car classes in every Safari track.
Lakeside Time Attack (20 points): In Time Attack mode beat the target times for all car classes on the Lakeside 1 Track.
Arctic Time Attack (20 points): In Time Attack mode beat the target times for all car classes in every Arctic track.
Alpine Time Attack (20 points): In Time Attack mode beat the target times for all car classes in every Alpine track.
Canyon Time Attack (20 points): In Time Attack mode beat the target times for all car classes in every Canyon track.
Tropical Time Attack (20 points): In Time Attack mode beat the target times for all car classes in every Tropical track.
Head to Head (20 points): Race on all the tracks in head to head mode.
Live Novice (10 points): Complete 10 races on Xbox Live.
Live Veteran (30 points): Complete 100 races on Xbox Live.
5 Ranked (30 points): Win 5 races in Xbox Live ranked matches.
10 Ranked (50 points): Win 10 races in Xbox Live ranked matches.
Social Hoster (30 points): Complete 100 races on Xbox Live as a Host.

Additionally, there are five secret achievements, all of which are currently unknown.