Under Campain -> Mission Challenge, the four challenges you need for this trophy are:
1-7
2-2
3-5
4-4
Focus on driving as smoothly as possible to keep from unnecessarily losing speed. On the last one with the Veyron, you will need to draft other cars to be able to reach the gold medal speed so stay behind each car briefly but make sure you don’t make contact with any of the cars or the walls because you will lose speed and not be able to hit the gold target.
You will also have to complete other challenges with at least a bronze medal to unlock the later events. Once you attain the gold medal on each of these 4 challenges, the trophy will unlock.