Here is the full list of all 46 Car Mechanic Simulator 2021 achievements. It takes around 120-150 hours to unlock all of the achievements on Windows.
Buy new car in car salon
Reach level 50
Buy 25 cars from impact cars
Buy 5 cars from impact cars
Visit Barn 30 times
Renovate and sell 50 cars
Buy 30 cars from barn
Paint 60 cars
Unlock 10 parking alleys
Unscrew 10 000 bolts
Unlock all upgrades
Finish 100 orders
Finish all the special missions
Finish path test 25 times
Buy 30 cars from junkyard
Sell 1000 parts from inventory
Reach level 20
Visit Salon
Buy 3000 parts from main shop
Finish lap with time under 1:50
Balance 50 tires
Earn 2000 scrap parts
Renovate and sell 1 car
Swap engine
Earn 50 000 CR on sell cars
Fix 150 body parts
Paint 5 cars
Buy 1 car from junkyard
Visit a junkyard
Earn 5000 CR on sell cars
Fix 50 body parts
Finish test track
Reach level 3 of garage expansion
Fix 150 car parts
Buy 1 car from barn
Visit Barn first time
Finish path test first time
Fix 50 car parts
Balance 5 tires
Earn 500 scrap parts
Pour old oil on the floor
Reach level 5
Finish order with experience bonus
Buy 100 parts from main shop
Finish order with money bonus
Finish 1 order