For rear wheelies: Mr. C For front wheelies: Letter F For boost multiplier: Sir Colin For speed: The Wheel For airtime: The Man With No Brakes As far as the boss battles go, upgrade your speed and acceleration as much as possible to start. What I did to beat them was simply to hold forward and accelerate (right key + w) and try to avoid falling. This will cause you to hit the rocks but you'll be able to avoid the enemy by recovering quickly.