- Change any 2WD car into 4WD
Wear out your tires, then do a burnout in your highest gear. Once the RPMs are in the red, downshift into first (i.e. one downshift will put it into first). Keep the brake on during this. If done correctly, you will have all wheel drive.

- North America reward cars
Reach the indicated level in North America to unlock the corresponding car:

2005 Chevrolet #31 Whelen Enigneering Corvette Z06	Level 35
1970 Chevrolet Chevelle SS-454	Level 15
1968 Shelby Mustang GT-500KR	Level 5
1996 Chevrolet Corvette Grand Sport	Level 25
1999 Dodge Viper GTS ACR	Level 30
1969 Dodge Charger R/T-SE	Level 10
2000 Ford Mustang Cobra R	Level 20
2002 Saleen #11 Graham Nash Motorsport S7R	Level 45
2002 Cadillac #6 Team Cadillac NorthStar LMP-02	Level 50
2005 Panoz #51 JML Team Panoz Esperante GTLM	Level 40

- Amateur Race Series reward cars
Get first place in the indicated race in the Amateur Race Series to unlock the corresponding car:

Mugen S2000	Free-Breathing Challenge
1992 Toyota Do-Luck Supra	Boosted Shootout
#22 3R-Racing Viper Competition Coupe	5X5 V10 Super Sprint
2000 Acura VIS Racing Integra Type-R	Inline 4 Showcase
2002 Chevrolet Lingenfelter 427 Corvette	Big Block Shootout
1973 Porsche 911 Carrera RS	Sports Car Classic
2002 Nissan Tommy Kaira Skyline GT-R R34	6-Cylinder Showoff
ME Four-Twelve Concept	Extreme Performance Shoot-Out
Corvette Goldstrand Edition	American Iron Runoff
VeilSide Supra Fortune 99	20th Century Supercar Invitational

- Achievements
Do the following things to obtain the corresponding Gamerscore points:

1 Points
All Cars from Korea	Acquire all of the cars from Korea in your Career garage.
All Cars from France	Acquire all of the cars from France in your Career garage.
All Cars from Spain	Acquire all of the cars from Spain in your Career garage.
2 Points
All Cars from Sweden	Acquire all of the cars from Sweden in your Career garage.
5 Points
Natural	Awarded to the single driver who wins the race with all Assists turned off.
Hard Charger	Awarded to the driver who begins in 8th place and comes in 1st place.
Crushing Victory	Awarded to any driver who finishes the race with a lapped opponent.
Level 1	Reach Level 1 in Career mode.
Hardcore	Awarded to the single driver who wins the race with full Difficulty, including no Assists.
Underdog	Awarded to the driver who wins the race with a car in the lowest PI of the field.
Car Level 5	Achieve a car level of 5 in Career mode.
Blowout	Awarded to the driver who wins the race, beating the rest of the field by a full race section.
All Cars from the United Kingdom	Acquire all of the cars from the United Kingdom in your Career garage.
10 Points
All Cars from Italy	Acquire all of the cars from Italy in your Career garage.
15 Points
All Cars from Germany	Acquire all of the cars from Germany in your Career garage.
All Gold (Proving Grounds)	Achieve a gold medal in every Career event of the Proving Grounds Race Type.
All Bronze Arcade	Achieve a bronze medal in every Arcade Race.
Level 10	Reach Level 10 in Career mode.
20 Points
Level 20	Reach Level 20 in Career mode.
All Gold (Manufacturer Club)	Achieve a gold medal in every Career event of the Manufacturer Race Type.
Car Broker	Buy or sell 10 cars online in the Auction House.
25 Points
All Gold (Amateur Cup)	Achieve a gold medal in every Career event of the Amateur Race Type.
All Silver Arcade	Achieve a silver medal in every Arcade Race.
All Cars from the United States	Acquire all of the cars from the United States in your Career garage.
30 Points
1,000,000 Online Credits	Gain 1,000,000 'Online Credits' from Tournaments and Career races.
All Cars from Japan	Acquire all of the cars from Japan in your Career garage.
Level 30	Reach Level 30 in Career mode.
All Gold (Rivalry Face-offs)	Achieve a gold medal in every Career event of the Rivalry Race Type.
35 Points
All Gold (Semi-Pro Events)	Achieve a gold medal in every Career event of the Semi-Pro Race Type.
All Gold Arcade	Achieve a gold medal in every Arcade Race.
40 Points
Level 40	Reach Level 40 in Career mode.
All Gold (Factory-Spec)	Achieve a gold medal in every Career event of the Pro Spec Race Type.
All Time Trials Set	Clear the target time in every Time Trial race.
50 Points
Level 50	Reach Level 50 in Career mode.
All Gold (Regional Championship)	Achieve a gold medal in every Career event of the Regional Championship.
60 Points
All Gold (Professional Series)	Achieve a gold medal in every Career event of the Pro Series Race Type.
70 Points
All Gold (Endurance)	Achieve a gold medal in every Career event of the Endurance Race Type.
75 Points
All Gold All Race Types	Achieve a gold medal in every Career Race Type.

30 Points
Secret Acquireor 3	Acquire all race cars.
Secret Acquireor 1	Acquire all production cars.
Secret Acquireor 2	Acquire all tuner cars.
Secret Acquireor 4	Acquire all cars, including tuners and race cars.

- Easy Endurance race wins
Go to any Endurance race, and enter it. Hire the cheapest driver, then go to the difficulty settings. Change each setting so that it will give you a bonus, except for the difficulty of the AI drivers. Change the AI to easy and begin the race. All you have to do now is wait.

- Asia reward cars
Reach the indicated level in Asia to unlock the corresponding car:

2005 Honda NSX-R GT	Level 30
1998 Subaru Impreza 22B STi	Level 15
1969 Nissan Fairlady Z 432R	Level 5
1999 Toyota #3 Toyota Motorsports GT-ONE TS020	Level 50
2002 Mazda RX-7 Spirit R Type-A	Level 25
1998 Nissan #32 NISSAN R390 GTI	Level 45
2002 Nissan Skyline GT-R V-Spec II Nur	Level 20
2004 Mitsubishi Lancer Evolution VIII MR	Level 10
2003 Subaru #77 CUSCO SUBARU ADVAN IMPREZA	Level 35
2006 Toyota #25 ECLIPSE ADVAN SUPRA	Level 40

- Proving Grounds Series reward cars
Get first place in the indicated race in the Proving Grounds Series to unlock the corresponding car:

2004 Honda Be victorious ings West Civic Si	AWD Shootout
1985 Toyota AE86 Sprinter Trueno	Asian Open
1969 Chevrolet Camaro Z28	North American Open
1992 Lancia Delta Integrale EVO	RWD Shootout
1994 Honda Do-Luck NSX	Flyweight Invitational
1970 Porsche 914/6	European Open
1995 Toyota Border MR2 Turbo T-bar	Mid-Engine Challenge
2003 Renault Sport Clio V6 RS	Hot Hatch Runoff
2001 Mazda Mazdaspeed Roadster	FWD Shootout
2007 Shelby GT500	Heavyweight Open

- Infinite money
Notice: This trick will only work if your game has not been patched through Xbox Live. Select any car. Buy the upgrade second to the last. After buying it, reinstall the stock part, and there should be a blue check on the purchased part. Go to it, then push RT + X as you are selling the part you just purchased. It should move over to the one on the end. You will receive the money for the one on the end, and the one that you purchased should still be there. You can repeat this as many times as desired. Notice: If you have already bought the best upgrade, this glitch will not work; instead, it will sell the best upgraded for the sell price.

- Semi-Pro Series reward cars
Get first place in the indicated race in the Semi-Pro Series to unlock the corresponding car:

2006 Panoz #81 Team LNT Esperante GTLM	Panoz 500HP
1998 Subaru Tommy Kaira Impreza M20b	Goodyear 150HP
1995 Mazda AB Flug RX-7	Kumho 250HP
2003 Dodge #23 Viper Comp Coupe	Stoptech 400HP
2003 Mitsubishi Sparco Lancer Evo VIII	Sparco 200HP
1998 Nissan R390	Nissan 350HP
2004 Volvo #24 At-Speed S60-R	Toyo 450HP
2006 Audi #2 FSI Champion Racing R8	K&N 700HP
2005 Maserati #35 Risi Comp MC12	Risi Comp 600HP
2007 Peugot 207 Super 2000	Castrol 300HP

- Europe reward cars
Reach the indicated level in Europe to unlock the corresponding car:

Audi #1 Infineon Audi R8	Level 50
1982 Porsche 911 Turbo 3.3	Level 15
1961 Jaguar E-type S1	Level 5
1987 Porsche 959	Level 25
1989 Lotus Carlton	Level 20
1974 Lancia Stratos HF Stradale	Level 10
1998 Ferrari F355 Challenge	Level 30
2005 Porsche #3 Lechner Racing School Team 1 911 GT3 Cup	Level 35
2005 BMW Motorsport #2 BMW Motorsport M3-GTR	Level 40
McLaren #41 Team McLaren F1 GTR	Level 45

- Manufacturer Club Series reward cars
Get first place in the indicated race in the Manufacturer Club Series to unlock the corresponding car:

2005 Chevrolet #99 Tiger Racing Corvette Z06	Corvette Touring Cup
1999 Lamborghini Diablo GTR	Running of the Bulls
1967 Ferrari 330 P4	Club Ferrari
2000 Audi AWE S4 Tuning Silver Bullet S4	Audi Cup
2000 Dodge Hennessey Viper 800TT	Viper Performance Cup
1995 Toyota VIS Racing MR2 Turbo T-bar	MR2 Cup
2000 Nissan Top Secret D1-Spec S15	Nissan Racing Club
2003 Volkswagen Golf R32	Volkswagen Driver's Club
2002 Honda Mugen Integra Type-R	Integra Cup
2006 Porsche #82 Red Bull 911 GT3 Cup	Porsche Sports Car Club

- Easy money
Level up any five Porsches (even the R class). If you still have the Chrysler ME-Four Twelve, select it, then go to 'Improves' and 'Tires'. Select the Perrell tires, and they should be 50% off, costing about 17,000 CR. Buy them, then sell them for 21,000 CR.