I challenge you to go over the Others tab in the Challenge section ^^ and check out the cool types of races we have there. Latest one - The Dumbest Bot Ever - was posted by yours truly just now, and just like any task it can be quite fun and spice up a bit your races. 

Also, take the time to go over the comments section in the challenge of your choice. Useful info can be found there, not to mention the All TT’s tab and all advice led by our own alien drivers.

Enjoy.