FUEL

This one is quite easy. You will need 2 people or a second x-box & 2 copies of the game. First create an xbox party room for both players, as this will make it easier to get both players in the same lobby.

The player hosting needs to go into the x-box live multiplayer tab and select "play x-box live", then select "player match" and then "create session". Now select the very first race "The Leap of Faith" and set the max entrants to 2 and "friends only" Select the vehicle, livery, etc. to get to lobby screen. Now you need to bring up the dashboard screen on your xbox (don't exit the game) and go down to "party", bring up the party screen and use the "invite party to game" option

This will send a game invite to the other person and bring him straight into the game lobby without him having to search. He now selects his vehicle to get into the lobby, the second player starts the game and sits at the start line letting the one needing the achievement win the race. Repeat 30 times and the achievement should unlock.

To add on to Canadabug's solution,

I found that using the course "Coming in from the Cold" will be a faster time than "The Leap of Faith" course.

Coming in from the Cold w/ 1 lap on the Valkyrie bike roughly takes 40-50 seconds.
The Leap of Faith on Valkyrie bike roughly takes 1:15-1:25 minutes.