4

Unstoppable
Finish first in every race in the Ultimate Speed Pack (Single Player)

Snake Bite
Shut down the Hennessey Venom GT Spyder (Single Player)

Uncanny
Unlock 'Supersonic', 'Super Powered', 'Super Natural', and 'Super Freak' License Plates (Multiplayer)

Sidekicked
Takedown an opponent with 'Ultimate Fan' as you License Plate (Multiplayer)