Accolade Pictures:
At the beginning go the reversed mojave track, turn around backwards and go to the right of the sand pile. Keep driving for a little while and you will see a big sign that says accolade and it has a bunch of peoples pictures on it!Extra Vehicles

To get a School Bus:
Select either single race or world tour mode. Then, on the transmission select screen, hold the Select button and press L1, Up, L2, Down, Down, L2, L2, R2.

To get an Ice Cream Truck:
Select either single race or world tour mode. Then, on the transmission select screen, hold the Select button and then press R2, L2, L2, Down, Down, L2, L2, R1.

All Cars & Tracks:
At the main menu, hold Select and then press L1, Left, L2, Right, L2, Left, L1, L1.

Drive a Black Widow:
On the transmission select screen, hold Select and then press R1, L2, L2,Down, Down, Up, L2, L1.