Enter the Professional Mode
At the select screen select arcade mode highlight the hard setting. Now you need to hold L1 & R1 until the setting changes to the word Professional. Then simply choose this mode and save the game, once the game is saved there is no need to do this when you start playing again. The only reason you would need to it again is when starting a new game.
Unlock the Aston Martin Vanquish
Win the British GT Car Cup in the Professional League. Of course you need to enter the cheat above before this can happen.
Unlock the Audi S4
A great car to use and simple to unlock, just win the British GT Car Cup in the Professional League.
Unlock the Audi TT 1.8T Quattro
In the Beginner League win the Tourist Trophy Audi TT Race and this one is ready to use.
Unlock the Celica TRD Sports M
Win the FF Challenge in the Amateur League and this is also ready to use.
Unlock the Chevrolet Camaro SS
This Muscle car can be unlocked by winning the Stars and Stripes Grand Championship in the Beginner League.
Memory Card ATM Trick / Glitch
You will need two memory cards for this to work. After you have earned over 200,000 credits, purchase any expensive car and then upgrade it up to the max. This will leave you almost broke. Go home and save this car to memory card slot two, then return to the title screen and load your last game from memory card slot one. This will give you your money back, and you can now go home and trade from memory card slot two.
The car that you just spent all those credits on will now only cost the price of the car. It is like being able to buy upgrades for free. This can be repeated but use some caution and care as with any glitch or trick using any memory cards, the risk of losing all your hard work and other saves is there.
Mo Money Trick / Glitch
Hey man low on the cash flow? Here is a neat little tip to earn some fast cash. Go to Super Speedway in the Beginner League and keep racing the same level. No matter how many times you race the event you will earn the same amount each time. While this method is not fast it can help you have a decent cash flow to work with for the rest of the series. Once you're low again, simply repeat the trick.