-To easily gain money, enable the UNLOCKALLTHINGS code and go to the car lot to find a red Acura Integra for $0. Sell it for $7,000 as many times as you want.
-To easily gain money, load your career profile and enable the UNLOCKALLTHINGS cheat. Save your career. Reload it and go to the garage. You will have unlocked several expensive cars. Sell the bonus cars to earn more than $90,000. Repeat as desired.
-Use the following trick to get $91,500 in a few minutes:
1. Enter Career mode. Select the "Secret Code" option at the menu. 2. Enable the "Master Code". 3. Go to any Race Day. 4. Immediately leave the Race Day. 5. Go to the garage. Notice that you now have four cars unlocked: the Pontiac GTO, Chevrolet Cobalt SS, Dodge Viper SRT10, and Nissan 240SX. 6. Sell them all. You can get $91,500 in total. 7. Quit the game. 8. Start the game again. 9. Repeat steps 1 through 4. 10. Those four cars will respawn in your garage. 11. Sell them all again.