Car Mechanic Simulator 2021

Once you hit level 5, you can head over to the Junkyard. From there, just buy the cars that are spread around the junkyard. Once you buy 30 of them, achievement will unlock.

Almost all of the time, if you have unlocked the car wash upgrade, and the welder, you can wash the interior and exterior of the car, along with repairing the body, and your junkyard purchase will be worth more than you paid for it. Buy as many junkyard cars as you can afford/store, wash and repair them, and sell them for $1000+. Easy way to make money early in the game.