For this achievement you can win against AIAs this one requires you to win a circuit race in an online game on
Nürburgring Nordschleife, a 1 lap race against AI is the fastest way.
To create a game:
-Community
-Race Online
-Create Race
-Game setup
-Game Type - Circuit Race
-Environment - Nürburgring
-Track - Nordschleife
-Max Players - 2
-Max AI Players - 1
-Laps 1
-Car Class - Any
Then select your car the
2012 Porsche 911 GT2 RS and change the AI car to something slow.
Start the race and win for the achievement.
Here's a video, you do not have to own the car.