Need for Speed Unbound

This achievement requires you to fully upgrade your garage in story mode.

You'll need a total of $157,500 to be able to upgrade from Sport > Pro > Super > Elite. You need to unlock the previous tier of the garage before the next one becomes available to unlock.

You shouldn't have much of a problem doing this in story mode. If you're doing as many races as you can every day and night, you should have enough money to unlock this before the third qualifier. If not, the third qualifier pays out $200,000 so that will give you more than enough. I'd focus on getting this out of the way as soon as you can though, as it allows you to upgrade your cars with the best parts in the game.

As soon as you purchase the last upgrade, you'll unlock your achievement.