I'm afraid there are NO cheats for Gran Turismo, the only cheats that I have seen are bogus ones that do not work (like the extra 300,000 credits one), but there is a bug in GT that lets you fit free parts. However I can give you some helpful tips on how to play through the game.
When you start the Gran Turismo mode, the first thing you have to do is buy a 2nd hand car. The best car to buy is the Mazda RX-7 GT-X.
Once you have got your car, you need to get a licence in order to be able to race it (see below). When you have obtained the B-Licence go to the race menu and choose the Sunday Cup. When you have won enough credits, go back to the Mazda garage and purchase some Racing Soft/Soft tyres, this will make your car handle better, and you should now be able to win the tournament every time.
Your next aim is to buy a new car. My personal preference is the Dodge Viper GTS. Just keep on doing the Sunday Cup until you have enough Credits.
It seems there is a bug in GT which means you can make free duplicate copies of any parts you buy for a particular type of car. Try this:
NOTE:
This won't work for the Weight Reduction or Racing Mod options
and a few other things (like port polishing), as these are not
available from the Change Parts menu - they're not really
"parts" as such anyway.
Also, it doesn't seem to work with cars that have been won.
Of course the best thing you can do with this is sell the extra cars. As it cost you nothing to increase its specs, you make a profit when you sell it!
The easiest way to gain extra credits is to race and win each Cup or Challenge more than once, and then sell the extra Bonus Cars you receive.
If you are really stuck on a particular stage leave GT Mode and return to the front menu. Choose "Replay Theatre" and then choose Demonstration, you can now choose the particular stage you are stuck on and you will see a demo run of it.
Sunday Cup - Mazda Demio A-Spec Clubman Cup - Camaro Z28 30th Anniversary GT Cup - Toyota Chaser LM Edition GT World Cup - GT Hi-Fi Mode (better graphics) FF Challenge - CR-X EF-8 SiR FR Challenge - Sil Eighty Silvia Q's 1800cc 4WD Challenge - Lancer GSR Evolution IV Alcione SVX S4 Lightweight - Civic Type R Eunos Roadster US v Japan - Mitsubishi FTO LM (4WD) Dodge Viper GTS-R UK v Japan - Honda CR-X Del Sol LM (MR) TVR Cerbera LM Edition UK v US - RX-7 A-Spec LM Edition Chrysler (Dodge) Concept Car Megaspeed - Soarer 2.5GT-T VVT-i Aston Martin DB7 Coupe Normal Car - Impreza '96 Sedan WRX Sti ver. III Supra RX Tuned Car - AE86 Sprinter Trueno GT APEX R32 Skyline GT-R '91 Grand Valley 300 - Castol Supra GT All Night 1 - S14 Silvia LM Edition All Night 2 - Nismo GT-R LM Edition (FR) All Gold in :- B Licence Test - Chrysler (Dodge) Concept Car A Licence Test - TRD 3000GT IA Licence Test - Nismo 400R
Best All Rounder
AN FTO Limited Edition combines power, reasonably light
weight, 4WD and impressive top speed to devastating
effect