Acquire 75,000 Credits:
Input the code: !MegaWedge!

Acquire Fireball:
Complete the P2P with bike on expert difficulty.

Acquire All Tracks:
Input the code: TraxAhoy

Acquire All Sponsors:
Input the code: uDunGud

Chimera:
Complete P2P with the truck on expert difficulty.
 
Fresh Treds:
Input the code: newtreds