i did it this way:
- second controller (make a new player)
- multiplayer
- splitscreen quick race
- beginner
- fightrace (dont realy know how it called in english)
- paradiso
- track 1
and then you only must race. at the start i pressed the second players accelerator-button. after you win, you can race with the second player and finish the race.
you get the achievement after the timelist.