All Gates Opened:
Enter Exploration mode and beat three laps. Then, enter OPN as a name. Hold L1 + L2 + R1+ R2 and press X at the "OK" prompt to confirm the name.

Receive Power-up When Entering a Gate:
Enter Exploration mode and beat three laps. Then, enter POW as a name. Hold L1 + L2 + R1+ R2 and press X at the "OK" prompt to confirm the name.

Slow Motion:
Enter exploration mode and complete three laps. Then, enter SLO as a name. Hold L1 + L2 + R1+ R2 and press X at the "OK" prompt to confirm the name.

Alternate Views:
Select Time Attack mode, choose any track, and enter CAM as a name. Hold L1 + L2 + R1+ R2 and press X at the "OK" prompt to confirm the name. Exit the track and press L1 to access three new views.

Better Traction:
Enter Exploration mode and beat three laps. Enter "END" this time. Hold L1 + L2 + R1+ R2 and press X at the "OK" prompt to confirm the name.

Thanks to Revolution readers Danny Youakim and Grasshopper!