On The Bubble Trophy

In a Last Man Standing race, the person who is last gets eliminated every 20 seconds, the timer will appear on the screen when this is about to happen and it will glow red if you are last. At the start ensure you are in front of the last person, when they get eliminated quickly overtake the next person, and continue this process until finally you overtake 1st place leaving them in 2nd and subsequently eliminated. Change the difficulty to easy if this causes you trouble, the AI are pretty slow and easy to overtake.