WRC: FIA World Rally Championship

The earliest you can unlock this is in Level 7 - Race 4 but this can be obtained later in the game if you skip this event until the end. (Cannot be missed)

Having progressed through each level prior to Level 7 you should have impressed the Adapta World Rally Team enough to be able to select their Subaru Imprezza for the event.

The achievement will unlock after you have selected them and the race has started to load.

In the Road to the WRC, once you hit lvl 10 you can choose a WRC Team. Thats when the achievement pops up
Can't miss it.