Here is the full list of all 45 Flatout 3: Chaos & Destruction achievements.
Win all Speed tracks
Win all races.
Win all Uranium Mine races.
Win all Harbor races.
Win all Vienna races.
Win all Outdoor races.
Win all Rome races.
Complete all splatout levels.
Score a 60 hit combo.
Get a score of 7 million.
Score a 50 hit combo.
Score a 40 hit combo.
Score a 30 hit combo.
Score a 20 hit combo.
Score a 10 hit combo.
Kill one zombie.
Win on a Speed track.
Drive into water.
Win all Detroit races.
Be destroyed by a train.
Win on a reversed track.
Win a race.
Win a Nightshift race.
Win a Golf stunt.
Win an Industrial stunt.
Win a Nightmare stunt.
Win all Nightshift races.
Finish a Nightshift race as loser.
Win a Monstertruck challenge.
Win all Monstertruck challenges.
Win all normal Battle Arenas.
Win all Big Battle Arenas.
Win all Kansas Offroad races.
Win all Utah Offroad races.
Complete all stunts.
Win a normal Battle Arena match.
Win a Big Battle Arena match.
Win all Offroad races.
Play a multiplayer game.
Complete a challenge.
Complete 25 challenges.
Complete all challenges.
Kill 10000 zombies.
Score a 100 hit combo.
Score a 150 hit combo.