Win Streaks are an element of multiplayer introduced in a 2013 update along with the Daily Bonus system. The Win Streak system rewards winning racers by awarding them with special prizes for each successive win. Once a player has won 9 games in a row they are rewarded with the highest prize, and then the process will repeat itself.
The successive prizes vary, but these are some typical rewards you should expect to win-
- 9 wins - 7,500 or 1x Class C Upgrade. Occasionally you can also win a 1x free nitro starter, although this is uncommon--no more 7,500 credits and a free nitro starter is quite common June 2015.
After 9 consecutive wins, or if you lose a race (finish in fourth through eighth place) you will be forced back to square one.
If the player leaves the multiplayer menu in their 6th win, the Class D upgrade will very likely change it to 5,000 credits while a Class C upgrade will change into a free nitro starter.