QUOTE
Quick HP boost
For a quick HP boost, immediately after buying a new car in sim mode...take it to the garage and change the oil. should give a some free horsepower!
Get Cash
After winning amatuer NA race save to memory card two then go back to the amatuer NA then save to memory card one then dont spend money.
Motorbike
L1, R1, R3 (push right analogue stick in), R2 THEN X, X, Triangle. Do this at car selection screen in arcade
Easy Money
A good way to get money is to buy an R-Type Integra and play on the R-Type series race in Beginner mode. It's really easy if you upgrade the car as much as possible. You get 5000 per race and 10000 at the end, 35000 already, then at the end you get an acura, which you can sell for 75000. 110000 in about 20 mins!
Codes
Professional Mode
First, choose Arcade Mode. Then highlight the the Hard difficulty level.
Hold L1 + R1, and it will change to Professional.
None of em tested so they probely wont work