Bonus cars
Have a saved game file from the original DiRT to unlock the Subaru Impreza STi Group N - No Fear (Gold).

Successfully complete the indicated event to unlock the corresponding car:

Colin McRae Challenge: 1995 Subaru Impreza WRX STi with chrome Colin McRae Livery
World Tour - Landrush: Toyota Stadium Truck
World Tour - Raid: Mitsubishi Pajero Dakar 1993
World Tour - Rally Cross: Ford RS200 Evolution
World Tour - Trailblazer: Dallenbach Special
X-Games - All Completed: Ford Escort MKII and MG Metro 6R4
X-Games - Asia: Mitsubishi Lancer Evolution with X-Games Livery
X-Games - Europe: Colin McRae R4 with X-Games Livery
X-Games - North America: Subaru Impreza WRX STi with X-Games Livery

Trophies
Successfully complete one of the following tasks to get a trophy:

All-Star (Silver): Win an All-Star division event.
Aren't You Popular! (Bronze): Become true friends with 4 superstars.
As Good As It Gets (Silver): Reach Level 30 in the DiRT Tour.
Best Friends Forever! (Silver): Become true friends with every superstar.
Big Bucks! (Silver): Earn those big bucks.
Block Party (Bronze): Beat Ken Block in a Throwdown.
Dedication (Gold): Win every event in the DiRT Tour.
Dialled In (Bronze): Win a race using a custom vehicle setup.
Dominated! (Bronze): Win a domination event, getting the maximum available points.
Famous (Bronze): Reach Online Fame Level 15.
Five Of Your Best (Bronze): Win 5 Pro Tour races online.
Friends For Life (Bronze): Become true friends with a superstar.
Gate Crashed! (Bronze): Hit every gate in a Gatecrasher event.
Getting A Reputation (Bronze): Reach Level 15 in the DiRT Tour.
Gnarly! (Bronze): Finish with Flair! Cross the finish line with no more than two wheels touching the ground.
Gut It Out! (Bronze): Win a DiRT Tour event without winning a race.
Head Over Wheels (Bronze): Roll your vehicle and still win the race.
I Ain't Afraid Of No Ghost! (Bronze): Choose a ghost, download and beat it!
I like a Challenge (Bronze): Win 12 Throwdowns.
In His Footsteps (Bronze): Win 25 Rally races in the DiRT Tour.
Jet Setter (Bronze): Compete in a race in every location.
Keep It Clean! (Bronze): Win a DiRT Tour race without crashing.
Mirra Image (Bronze): Beat Dave Mirra in a Throwdown.
Mix It Up! (Bronze): Play in every discipline online (Pro Tour or Jam Session).
Nailed an Event (Bronze): Win an event.
Notorious (Silver): Reach Online Fame Level 30.
On The Bubble (Bronze): Be second to last at each elimination point but go on to win a Last Man Standing race.
Perfect finish! (Platinum): You've unlocked every other trophy - Congratulations!
Piece Of Cake (Bronze): Win a Throwdown.
Pro (Bronze): Win a Pro division event.
Rookie Coming Through! (Bronze): Race in your first DiRT Tour race.
Rush Hour (Bronze): Win a Pro Tour race online against 7 competitors.
Showboating (Bronze): Bask in your success at X Games America.
Terminated! (Bronze): Take terminal damage while travelling at over 140mph (225km/h).
That All You Got? (Bronze): Win a Timed Throwdown.
The Full Set (Silver): Drive every vehicle in the game.
Tourney (Bronze): Take part in four tournaments.
Two Cups One Girl (Bronze): Win two team events with the same female team-mate.
Whose Backyard? (Bronze): Beat Travis Pastrana in a Throwdown.
With Great Honor (Bronze): Achieve a 'Cautious' impact rating in Multiplayer races (Pro Tour or Jam Session).
World Tour Winner (Silver): Win all the World Tour events.
X Games America Champ (Bronze): Win X Games America.
X Games Asia Champ (Bronze): Win X Games Asia.
X Games Champ! (Gold): Win all the X Games events.
X Games Europe Champ (Bronze): Win X Games Europe.
You're The Best, Around! (Silver): Win a race at every track in the game (in any game mode).

Additionally, there are two secret trophies:

Just Drive! (Bronze): You drove 100 miles (161 kilometres) without unlocking any other trophy.
For Colin (Gold): You've won the Colin McRae Challenge Event.

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