You have to do this in Industrial & Bristol on sprint.
Drive until you get to the stadium, turn into the stadium, and go to the far right.
Then turn around going toward the track, but stick to the far right. You will see some arrows pointing to the direction of the track - go through them and then complete the race.
You wont complete it however, you will keep going and have full range of the city.
Note all people in the server have to do this for it to work or you will get the timer. Also if you enter the track again you have to do this over or you complete the race.
Have fun crusin around guys