Firstly, you need to unlock the showcase by completing the Seeker Championship and unlocking the Breakout Championship.
You will find the showcase on the bottom line inside the Breakout Championship.
After clicking to the race, you need to change the race length. Do this by pressing
and selecting assists. Go to the bottom and change the race length to
Extra Long.Change any other assists you see necessary, and also look at the Drivatar Difficulty.
You can change the skill level for Drivatars and receive additional credits: (This only affects the other racers skill and not your assist difficulty).
New Racer/Inexperience/Average +0%CR
Above Average +20%CR
Highly Skilled +40%CR
Expert +60%CR
Pro +80%CR
Unbeatable +100%CR.
Now you're ready to race! This is 69 laps and will take between 2¾ to 3 hours.
N.B. MODS are unavailable to use in this race. If leaving a negative vote, please comment why so I can look into adapting the solution.