Need for Speed ProStreet Cheats for Nintendo DS
Win a Raceday in Career mode that has the Hydraulics game as an event to unlock the Hydraulics mini-game.
This is a sneaky way of getting more money, to do it play the game so you are leading half way on a Raceday and you will be asked to choose from three random prizes. Select any of them to see what you get and when you are then asked if you want to keep dominating or leave the Raceday switch off the Nintendo DS and turn it back on again and continue your career. What will then happen is you'll be asked again to select a prize, this can be done as many times as you want.