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