Extra Cars:
Complete the button combinations before the title screen to unlock the following cars under Free
Race mode: 

     Honda - Hold R1 + Up + Square + Start on controller two 
     Castrol - Hold R1 + Square + Down + Start on controller two 
     Advan - Hold R1 + Triangle + Up + Start on controller two 
     Class 1 car - Hold R1 + Circle + Up + Start on controller two 
     Dunlop - Hold R1 + Down + Triangle + Start on controller two