anyone know of any cheats for gt4 on the ps2?

Answer 1

GT4 is slated to be released on the PS3...but GT4 on the PS2 is San Andreas:

http://www.gamefaqs.com/console/ps2/code/914983.html

Answer 2

Arcade Tracks
Play through X amount of days to unlock listed track in arcade mode.

Unlockable How to Unlock
Apricot Hill Raceway Days Completed = 169
Autumn Ring Days Completed = 281
Cathedral Rocks Trail I Days Completed = 239
Chamonix Days Complete = 309
Circuit de la Sarthe 1 Days Completed = 267
Circuit de la Sarthe 2 (Unchicaned) Days Complete = 351
Costa di Amalfi Days Completed = 253
Cote d Azur Days Completed = 183
Deep Forest Raceway Days Completed = 15
Fuji Speedway 2005 F Days Complete = 323
Fuji Speedway 2005 GT Days Completed = 141
Fuji Speedway 80s Days Completed = 43
George V Paris Days Completed = 225
Grand Valley Speedway Days Completed = 99
Hong Kong Days Completed = 113
Ice Arena Days Completed = 155
Infineon Raceway Stock Car Course Days Completed = 309
Opera Paris Days Completed = 29
Special Stage Route 5 Days Completed = 57
Suzuka Circuit Days Completed = 71
Suzuka Circuit West Course Days Completed = 127
Tahiti Maze Days Completed = 197
Tsukuba Circuit Wet Days Complete = 337
Twin Ring Motegi Road Course Days Completed = 211
Twin Ring Motegi Road Course East Short Days Completed = 85

Unlocakble Cars
To unlock the cars below, simply goto the Hall/Dealership(s) mentioned in the How To Unlock Tab

Unlockable How to Unlock
CHEVROLET Camaro IROC-Z Concept '88 Camaro Meeting (Chevrolet Dealership)
CHEVROLET Camaro LM Race Car '01 Stars and Stripes (American Hall)
CHEVROLET Chevelle SS 454 '70 American Muscle Car Championship (American Hall)
CHEVROLET Corvette Convertible (C1) '54 American Championship (American Hall)
CHEVROLET Corvette Stingray Coupe (C2) '63 Corvette Festival (Chevrolet Dealership)
PLYMOUTH Super Bird '70 Classic Muscle Car Championship (American Hall)
SHELBY Mustang G.T.350R '65 Shelby Cobra Cup (Shelby Dealership)

Showroom Unlockables

Unlockable How to Unlock
Acura HSC '04 Win Type R Meeting at Honda in the Japanese Showroom.
Alfa Romeo Giulia Sprint GTA 1600 '65 Win GTA Cup at Alfa Romeo in the Italian showroom.
Alpine A110 1600S '73 Win Renault Alpine Cup at Alpine the in the French Showroom.
Aston Martin DB9 Coupe '03 (Super Gold - Special Color) Win Aston Martin Carnival at Aston Martin in the British showroom.
Audi Le Mans quattro '03 Win Tourist Trophy at Audi in the German showroom.
Audi Pikes Peak quattro '03 Win A3 Cup at Audi in the German showroom.
BMW 2002 Turbo '73 Win 1 Series Trophy at BMW in the German Showroom
BMW M3 GTR '03 Win Club "M" at BMW in the German Showroom
Chevrolet Camaro IROC-Z Concept '88 Win Camaro Meeting at Chevrolet in the American Showroom.
Chevrolet Corvette Z06 (C2) Race Car '63 Win Vette! Vette! Vette! at Chevrolet in the American Showroom
Citroen 2CV Type A '54 (Peche - Special Color) Win 2HP - 2CV Classics at Citroen the in the French Showroom.
Clio Renault Sport Trophy V6 24V Race Car '00 Win Clio Trophy at Renault in the French Showroom.
Daihatsu Midget '63 Win Midget II Race at Daihatsu in the Japanese Showroom
Daihatsu STORIA X4 '00 (Special Color - Emerald Green Metallic) Win Copen Race at Daihatsu in the Japanese Showroom
Dodge VIPER GTSR Concept '00 Win Crossfire Trophy at Chrysler in the American Showroom
Honda HSC (Honda Sports Concept) '03 Win Type R Meeting at Honda in the Japanese Showroom. (U.S Version)
Honda MUGEN MOTUL CIVIC Si Race Car '87 Win Civic Race at Honda in the Japanese Showroom.
Hyundai Clix '01 Win Hyundai Sports Festival at Hyundai in the Korean Showroom.
Isuzu 117 Coupe '68 (Special Color - Maple Orange) Win Isuzu Sports Classics at Isuzu in the Japanese Showroom.
Lotus Elan S1 '62 Win Lotus Classics at Lotus in the British showroom.
Lotus Elise Type 72 '01 Win Elise Trophy at Lotus in the British showroom.
Mazda 110S (L10A) '67 Win Club "RE" at Mazda in the Japanese Showroom.
Mazda MX-Crossport '05 Win NR-A Roadster Cup at Mazda in the Japanese Showroom.
Mazda RX-8 Concept LM Race Car '01 Win NR-A RX-8 Cup at Mazda in the Japanese Showroom.
Mercedes-Benz CLK Touring Car '00 Win Legends of the Silver Arrow at Mercedez-Benz in the German Showroom.
Mercedez-Benz 300 SL Coupe '54 Win SL Challenge at Mercedez-Benz in the German Showroom.
MGF '97 (Yellow- Special Color) Win the MG festival at MG in the British showroom.
Mistubishi Lancer 1600 GSR Rally Car '74 Win Evolution Meeting at Mitsubishi in the Japanese Showroom.
Mitsubishi i '03 Win Mirage Cup at Mitsubishi in the Japanese Showroom.
NIKE One 2022 Win Saleen S7 Club at Saleen in the American Showroom.
NISMO GT-R LM Road Going Version '95 Win Race of the Red "R" Emblem at Nissan in the Japanese Showroom.
Nissan 240ZG (HS30) '71 Win Club "Z" at Nissan in the Japanese Showroom.
Nissan mm-R Cup Car '01 Win March Brothers at Nissan in the Japanese Showroom.
Opel Calibra Touring Car '94 Win Speedster Trophy at Opel in the German showroom.
Peugeot 205 Turbo 16 Rally Car e85 Win 206 Cup at Peugeot in the French showroom.
Renault AVANTIME '02 (Special Color - Jaune) Win Megane Cup at Renault in the French Showroom.
Shelby Mustang G.T. 350R '65 Win Shelby Cobra Cup at Shelby in the American Showroom.
SILEIGHTY '98 Win Silvia Sisters at Nissan in the Japanese Showroom.
Subaru IMPREZA Super Touring Car '01 Win Stars of Pleiades at Subaru in the Japanese Showroom.
Subaru SUBARU 360 '58 (WR Blue Mica - Special Color) Win Subaru 360 Race at Subaru in the Japanese Showroom.
Suzuki CONCEPT-S2 '03 Win Suzuki K-Car Cup at Suzuki in the Japanese Showroom.
Suzuki GSX-R/4 '01 Win Suzuki Concepts at Suzuki in the Japanese Showroom.
Toyota ALTEZZA Touring Car '01 Win Altezza Race at Toyota in the Japanese Showroom.
Toyota Vitz RS Turbo '02 (Special Color - Orange Metallic) Win Vitz Race at Toyota in the Japanese Showroom
TVR Cerbera Speed 12 '00 (Chameleon - Special Color) Win Black Pool Racers at TVR in the British showroom.
Volkswagen Beetle 1100 Standard (Type-11) '49 Win Beetle Cup at Volkswagen in the German Showroom.
Volkswagen Golf I GTI '76 Win GTi Cup at Volkswagen in the German Showroom.
Volkswagen Karmann Ghia Coupe (Type-1) '68 Win Lupo Cup at Volkswagen in the German Showroom.

Unlockable Cars in American Hall

Unlockable How to Unlock
CHEVROLET Camaro LM Race Car '01 Win Stars and Stripes
CHEVROLET Chevelle SS 454 '70 Win American Muscle Car Championship
CHEVROLET Corvette Convertible (C1) '54 Win American Championship
PLYMOUTH Super Bird '70 Win Classic Muscle Car Championship

Unlockable Cars in Beginner Hall

Unlockable How to Unlock
AUTOBIANCHI A112 Abarth '79 Win the Sunday Cup
CHEVROLET Silverado SST Concept '02 Win the Sport Truck Race
CHRYSLER Prowler '02 Win the Spider & Roadster
GINETTA G4 '64 Win the Light Weight K Cup
LOTUS Esprit Turbo HC '87 Win the MR Challenge
MAZDA 6 Concept '01 Win the FF Challenge (U.S Version)
MAZDA Atenza Concept '01 Win the FF Challenge
NISSAN SKYLINE 2000GT-B '67 Win the FR Challenge
TOYOTA Motor Triathlon Race Car '04 Win the 4WD Challenge

Unlockable Cars in Endurance Hall

Unlockable How to Unlock
AUDI Abt Audi TT-R Touring Car '02 Win Nurburgring 4 Hours Endurance
AUDI R8 '01 Win Sarthe Circuit 24 Hours I
Auto Union V16 Type C Streamline Win Grand Valley Speedway 300Km
BENTLEY Speed 8 Race Car '03 Win Sarthe Circuit 24 Hours II
Chaparral 2D Race Car ('67) Win Nurburgring 4 Hours Endurance
DODGE Charger Super Bee 426 Hemi '71 Win New York 200 Miles
FORD GT LM Edition '02 Win Infineon World Sport Car Trophy
FORD GT40 Race Car '69 Win Laguna Seca 200 Miles
HONDA NSX-R LM Edition Race Car '02 Win Super Speedway 150 Miles
HONDA NSX-R LM Edition Road Car '02 Win Motegi 8 Hours Endurance
LISTER Storm V12 Race Car '99 Win Suzuka 1000km
MAZDA RX-7 LM Race Car '01 Win Roadster 4 Hours Endurance
MITSUBISHI FTO Super Touring Car '97 Win Tokyo R246 300km
NISSAN R92CP Race Car '92 Win Fuji 1000km
NISSAN SKYLINE GT-R Race Car (CALSONIC) '93 Win Tsukuba 9 Hours Endurance
POLYPHONY Formula Gran Turismo '04 Win Nurburgring 24 Hours Endurance
TOYOYTA 88C-V Race Car (MINOLTA) '89 Win El Captain 200 Miles

Unlockable Cars in European Hall

Unlockable How to Unlock
LOTUS Europa Special '71 Win British Light Weight Car Race
MERCEDES-BENZ AMG CLK-GTR Race Car '98 Win German Touring Car Championship
ALFA ROMEO 155 2.5 V6 TI Race Car '93 Win Italian Festival
ALFA ROMEO Giulia Sprint Speciale '63 Win 1000 Miles
BMW M3 GTR Race Car '01 Win Schwarzwald League A
CITROEN 2CV Type-A '54 Win French Championship
JAGUAR E-Type Coupe '61 Win British GT Cup
JAGUAR XJ220 LM Edition '01 Win European Championship
MERCEDES-BENZ AMG 190E 2.5 16V Evolution II (DTM) '92 Win Schwarzwald League B
MERCEDES-BENZ Benz Patent Motor Wagen '1886 Win European Classic Car Championship
VOLVO 240 GLT Estate '88 Win European Hot Hatch Car Championship

Unlockable Cars in Extreme Hall

Unlockable How to Unlock
BMW MacLaren F1 GTR Race Car '97 Win Gran Turismo All Stars
FORD GT '05 Win Premium Sports Lounge
Mercedes Sauber C 9 Race Car '89 Win Formula GT World (US version)
NISSAN GRAN TURISMO SKYLINE GT-R (PaceCar) '01 Win Real Circuit Tours
NISSAN GT-R Concept LM Race Car '02 Win Dream Car Championship
OPERA PERFORMANCE S2000 '04 Win Polyphony Digital Cup
POLYPHONY Formula Gran Turismo '04 Win Formula GT World (Japanese version)
VOLKSWAGEN W12 Nardo Concept '01 Win Like The Wind

Unlockable Cars in Hard Special Condition Hall

Unlockable How to Unlock
FORD GT Concept '02 Win Tsukuba Circuit
FORD RS200 Rally Car '85 Win Rally d' Capri
LANCIA Delta S4 Rally Car '85 Win Rally d' Umbria
LANCIA STRATOS Rally Car '77 Win Chamoni
MITSUBISHI PAJERO Evolution Rally Win Cathedral Rocks (Trail II)
MITSUBISHI PAJERO Rally Raid Car '85 Win Tahiti
MITSUBISHI STRAION 4WD Rally Car '84 Win Grand Canyon
NISSAN BLUEBIRD 1600SSS Rally Car (510) '69 Win Ice Arena
NISSAN SILVIA 240RS Rally Car '85 Win Swiss Alps
PEUGEOT 205 Turbo 16 Evolution 2 Rally Car '86 Win George Paris
SUZUKI ESCUDO Dirt Trial Car '98 Win Cathedral Rocks (Trail I)

Unlockable Cars in Japanese Hall

Unlockable How to Unlock
HONDA LIFE STEP VAN '72 Win Japanese Compact Car Cup
MITSUBISHI HSR-II Concept '89 Win Japanese 80's Festival
NISMO 400R (R33) '96 Win Japanese 90's Challenge
NISSAN Fairlady Z Concept LM Race Car '02 Win Japanese Championship
NISSAN MOTUL PITWORK Z (JGTC) '04 Win Japanese GT Championship
NISSAN SKYLINE Hard Top 2000GT-R (KPGC10) '70 Win Japanese 70's Classic

Unlockable Cars in License Centre

Unlockable How to Unlock
NISMO 270R '94 (S14) Complete International A License
Acura DN-X '02 A License - All Silver or better (US Version)
DOME ZERO '78 Get All Gold in International A License
FORD Model T Tourer '15 Get All Golds in Super License
HONDA DUALNOTE '01 Get All Silver in Domestic A License (Japanese Version)
HONDA S500 '63 Get All Golds in Domestic B License
JENSEN HEALEY Interceptor Mk.III '74 Get All Gold in International B License
MAZDA KUSABI '03 Get All Silver in Domestic B License
MAZDA RX-8 Concept (Type-II) '04 Get All Silver in International B License
MERCURY Cougar XR-7 '67 Complete Super License
NIKE One 2022 Complete International B License
NISSAN GT-R Concept '01 Get All Silver in International A License
NISSAN SKYLINE GT-R '01 Get All Golds in Domestic A License
PONTIAC Solstice Coupe Concept '02 Get All Silver in Super License
PONTIAC Sunfire GXP Concept '02 Complete Domestic A License
VOLKSWAGEN Lupo 1.4 '02 Complete Domestic B License

Unlockable Cars in Mission Hall

Unlockable How to Unlock
DMC DeLorean S2 '04 Complete Missions 1-10
JAY LENO Tank Car '03 Complete Missions 11-20
NISSAN R89C Race Car '89 Complete Missions 30-34
PAGANI Zonda Race Car '01 Complete Missions 21-24
TOYOTA 7 Race Car '70 Complete Missions 25-29

Unlockable Cars in Normal Special Condition Hall

Unlockable How to Unlock
FORD Escort Rally Car '98 Win Tahiti
LANCIA Delta HF Integrale Rally Car '92 Win Rally d' Umbria
MAZDA 6 Touring Car '02 Win Tsukuba Circuit ( U.S Version)
MAZDA Atenza Touring Car '02 Win Tsukuba Circuit
MITSUBISHI CZ-3 Tarmac Rally Car '02 Win Grand Canyon
MITSUBISHI Lancer Evolution IV Rally Car'97 Win Ice Arena
RENAULT 5 Maxi Turbo Rally Car '85 Win George Paris
SUBARU IMPREZA Rally Car '01 Win Chamoni
SUBARU IMPREZA Rally Car '99 Win Cathedral Rocks (Trail I)
SUBARU IMPREZA Rally Car Prototype '01 Win Rally d' Capri
TOYOTA CELICA GT-FOUR Rally Car (ST185) '95 Win Cathedral Rocks (Trail II)
TOYOTA CELICA GT-FOUR Rally Car (ST205) '95 Win Swiss Alps

Unlockable Cars in Professional Hall

Unlockable How to Unlock
MERCEDES-BENZ Daimler Motor Carriage '1886 Win World Classic Car Series
NISSAN OPTION Stream Z '04 Win Tuning Car Grand Prix
CIZETA V16T '94 Win Supercar Festival
FORD GT LM Edition Spec-II '04 Win Gran Turismo World Championship
HONDA NSX-R Concept '01 Win Race of NA Sports
HONDA S800 RSC Race Car '68 Win World Compact Car Race
MAZDA BP FALKEN RX-7 (D1GP) '03 Win Race of Turbo Sports
MAZDA Mazdaspeed 6 '05 Win Clubman Cup (U.S Version)
MAZDA Mazdaspeed Atenza '05 Win Clubman Cup
RUF CTR Yellow Bird '87 Win Boxer Spirit

Unlockable Cars in the Easy Special Condition Hall

Unlockable How to Unlock
ALPINE A310 1600VE '73 Win George Paris
CADILLAC CIEN '02 Win Rally d' Umbria
FORD RS200 '84 Win Grand Canyon
HYUNDAI HCD6 '01 Win Cathedral Rocks (Trail II)
INFINITI FX45 Concept '02 Win Chamoni
LAND ROVER Range Stormer Concept '04 Win Cathedral Rocks (Trail I)
MAZDA RX-8 Concept (Type-I) '01 Win Tsukuba Circuit
MITSUBISHI CZ-3 Tarmac '01 Win Swiss Alps
RENAULT 5 Turbo '80 Win Tahiti
TOYOTA RSC '01 Win Ice Arena
TOYOTA RSC Rally Raid Car '02 Win Rally d' Capri

Unlockables

Unlockable How to Unlock
Audi Nuvotari Quattro '03 Complete 25% of game
Autobianchi A112 Abarth '79 Get all gold in all the races for the Sunday Cup
Jaguar XJ-R9 Race Car Complete 50% of the game
Mini Marcos GT '70 Get gold in Mini Mini Sports Meeting
NISMO Skyline GT-R LM Road Going Version Win the Race of the Red Emblem
Polyphony Formula Gran Turismo 04 (Black Version) Complete 100% of Gran Turismo Mode
Triumph Spitfire 1500 '74 (Special Color- Maroon Metallic) Win the Spitfire Cup at the Triumph dealer.

View Ending Movie
Win the Gran Turismo World Championship in Professional Hall.

Easter Eggs
2022 Nike One Morse Code
If you look really close on the side of the Nike One, you can see a small area near the front of the car of morse code. If you go into photo mode, this will become clearer. The morse code is written backwards as to be seen correctly from inside the car. Spelled out, it is " www.Phil-Frank.com " the website of the Phil Frank Automotive and Product Design Company. Phil Frank was paid to design the futuristic Nike car specifically for Gran Turismo 4.

Secrets
Free Horsepower
When you buy or win a new car, take it for an oil change. After the oil change, your car's horsepower will increase.

Hidden Black Cars
On days 694-700 in the used car lots you can buy special black versions of:
1.Toyota GT One Race Car
2.Mazda 787B
3.Nissan R390 Race Car
4.Nissan R92CP Race Car

To Buy them all it comes to roughly 9,000,000 credits

Licence Guides
To get a Blue (acceleration) and Red (brakes) Licence Test Guide simply push R3 during 3,2,1,Start. It shows you the best route to go and where to start braking. This only works on the B and A license tests and tests where there is no pace car.

Speed up replays, and turn off BGM
To speed up your replays simply press down L3 and to turn off the background music simply press O.

Stay in same gear in Automatic transmission
When using the automatic transmission option, hold R2 to make your car remain in the same gear. This is great for remaining at a given speed through a corner, or stretching the top end of a gear for a little extra speed/performance.