More of a useful tip than a guide, but try and get a group of people together for this one as the number of people in the race multiplies the number of races completed.
So, if you have 2 people, then it counts as 2 races completed for every 1 race.
If 3 people are in the race, then it counts as 3 races completed for every 1 race.
This method applies for everyone in the online race as long as they finish the race and don't get a DNF - in which case they get 0.
Have only been able to test this with 3 people in the race so I am only guessing it will apply for higher numbers than this.