Secret Battle Star 6 for the Road Trip Challenge unlocks after you complete any 6 weekly challenge sheets. This will unlock a loading screen with the secret battle star on it.
Secret Battle Star for week 6 can be found on the Red truck in front of the movie screen in Risky Reels.
All Week 6 Challenges
Deal Headshot Damage to opponents
Harvest building resources with a pickaxe
Search where the Stone Heads are looking (HARD)
Search Chests in Lonely Lodge (7)
Complete timed trials (5)
Minigun or Light Machine Gun Eliminations (HARD) (2)
Eliminate opponents in Tilted Towers (HARD) (3)