Unlock All Cars & Events
Go to Cheats Section from menu to enter codes:

Unlock All Cars
     [Up],  [Up],  [Up],  [Up], [Left], [Down], [Up], [Right], [Down],
[Down], [Down], [Down]

Unlock All Events
     [Start],  [Left],  [Select],  [Right],  [Right], [Triangle], [X],
[Square], [Start], [R], [Down], [Select]