Execute a Crazy Drift, wait until you have spun 180 degrees, then press Reverse + Drive.
You can earn as much as a 450 combo and $99,999.

Turn Off Arrow
To make the arrow that points you to your next destination disappear, hold R1 and press START before you see the character selection screen. You will see the words "no arrows" if entered correctly.

Turn Off Destination Mark
To switch off the glowing square that indicates your destination, press and hold, then press Start before you see the character selection screen. You will see the words "no destination" if entered correctly.

Unlock Another Day
To shake things up in the city and play "Another Day," press and hold R1. Keep holding it until you choose a taxi driver. You will see the words "another day" if entered correctly.

Unlock Expert Mode
To unlock the special Expert Mode, press and hold L1 and R1, then press START before you see the character selection screen. You will see the words "expert" if entered correctly.