The Crew Motorfest

In the activities menu, launch the grand race, and race past at least 12 players during your race. It won't be difficult, it's an online race with more than 20 players, it has to be done in the same race and it's not 12 different players, you could do it with the same opponent as long as it's 12 times.

When the race starts you will unlock the achievement of participating in a grand race