Unlock the net battle car:
     Get 100 hours of gameplay

Start faster:
     Get  the  RPM gauge go into the yellow area during the countdown.
When  the  count  is  2  then  hold the brakes. Then when it reaches 1
release the brake and accelerate as go comes.

Unlimited money:
     Win the first race and then save the game to your memory card Now
copy  it to the other memory and sell one then repeat it as many times
as you want

Unlock red car:
     Win a race online