Win JET-Board stadium challenge was a mission in Jak II. The mechanic wanted Jak to prove his worth for her racing team by testing her prototype JET-Board in the stadium challenge.
Walkthrough[]
See also: JET-Board game
Once you've picked up the JET-Board, go and follow Keira's instructions. You'll then be able to enter the actual stadium section where you need to obtain 15,000 points before you can complete this mission.