Here is the full list of all 46 FlatOut 4: Total Insanity trophies - there are 32 bronze, 10 silver, 3 gold and 1 platinum.
Jump at least 100m long with your car
Win a race with the maximum car parts on your car
Complete your first race in Arena Mode
Destroy your first opponent (offline)
Get all available skins for a Derby car
Hit 3 cars with the same activated weapon in Assault Mode
Use the 4 different weapons in Assault Mode
Empty all your nitro for the first time from full to empty
Win a race without crashing (100% Full HP)
Burn nitro continuously for at least 5 seconds in a race
Complete your First Cup in Career Mode
Destroy your car for the first time
Upgrade a car once
FlatOut Platinum
Buy at least two cars in each class, Derby, Classic and AllStar
Finish consecutively 10 times on podium in Career Mode
Earn 123456 cash in Career Mode
Destroy 20 Opponents Online
Kill Three opponents in the same race (offline)
Complete FlatOut Mode
Complete FlatOut Mode with all gold
Complete all stunts with bronze in FlatOut Mode
Complete all stunts with gold in FlatOut Mode
Complete Career Mode
Win an online race
Win 10 online races
Win 25 online races
Upgrade an AllStar car at the maximum
Purchase all cars of the game
Destroy 2000 breakables
Destroy 50 opponents (offline)
Slam 100 opponents in online races
Win 15 races in Arena Mode
Wreck 5 vehicles during a round in Arena Mode
Recover the flag 10 times in the Keep the Flag Mode
Win a race in Assault Mode
Win 5 races in Assault Mode online
Win 20 races in Assault Mode online
Beat a Time Trial with Gold in Career Mode
Win a race in Derby, Classic, All-Stars classes
Eject your driver 100 times
Drive a total distance of 500 miles
Score over 100,000 in a race
Make the perfect score in a stunt game
Keep the flag for 66 seconds in Keep the Flag Game Mode
Be both Survivor and Eliminator at the same time in 5 Arena Deathmatches