I have see this in the racing guide:
4. Keep doing thesis steps all the way to level 50, and reap great rewards of Splurt, special DNA, and fun and glory!

But I did not understand where and how to receive the rewards of SPURT! where ? when? how?
Who knows ? hihihihi ^_^ thank you

The splurt is applied to your account every 5 levels beginning at level 10.

Ok Thank you Asymmetrical :-)