Car Mechanic Simulator

After attempting to unlock this by using the junkyard and barn finds, fully renovating the cars and selling them I never unlocked this.

I unlocked it today, I bought a car from the auction and fully renovated that car. * Unlocked*

I am unsure if just increasing its overall states would unlock or if everything needs to be 100%.

I would find a car that has 100% in frame and body and only needs some parts fixed. When all 4 categories are 100%, sell it and you should have this pesky achievement.