Here is the full list of all 30 Carmageddon: Max Damage achievements worth 1,000 gamerscore.
Completed the Split Personality Mission
Customised your car by visiting the Parts Shop and buying a part
Finished a Classic Carma Event by Completing all the Laps
Achieved a Suck My Parts or Collateral Damage Bonus
Unlocked Chapter 2 in the Career
You completed the tutorial. You swot
Finished a Classic Carma Event by Wrecking all the Opponents
Wrecked your first Opponent
Complete the Mile Muncher Mission
Complete the Ped Popper Mission
Complete the They Don't Like It Up 'Em Mission
Kill 50 targeted Peds in Ped Chase
Wreck 100 Opponents in Car Crusher
Hit 100 Checkpoints in Checkpoint Stampede
Be the Fox for half an hour in Fox 'n' Hounds
Complete the Hotwiring Hotstuff Mission
Complete the MultiSlayer Mission
Finish a Classic Carma Event by Killing all the Peds
Get a x10 Ped Kill Combo
Achieve 60 Cunning Stunts
Collect 55 Smelly Bushes
Finish one Classic Carma Event in all three ways
Complete the Up Your Carma Mission
Complete the MP MegaPeep Mission
Complete 63 different Career Events on any Difficulty
Unlock Chapter 10 in the Career
Buy and Equip 12 Parts in the Parts Shop for one Car
Complete the Bulging Purse Mission
Kill 16,666 Peds
Complete 60 Laps in Death Race