When your tires are worn out do a burnout in your highest gear. When the RPMs are in the red downshift to 1st gear keeping the brake on the whole time. If you have done this correctly you will have 4 Wheel Drive.

The following cars are unlocked when you win the corresponding event.

Unlock Pagani Zonda C12:
Win the Professional (High-Power Open).

Unlock Porsche #26 Porsche AG 911 GT1-98:
Win the Endurance (Porsche 911 GT2 Cup).

Unlock Toyota Celica 1800 VVT-i:
Win the Amateur Front-Engine RWD Event.

Unlock Toyota VIS Racing MR2 turbo T-bar:
Win the Point-to-Point Mid-Engine Event.

Unlock Porsche 911 GT2:
Win the Point-to-Point (Club 911 Event).

Unlock Renault Sport Clio V6 RS:
Win the Amateur (Hatchback Challenge).

Unlock Porsche 911 Carrera RS:
Win the Professional (Class B Championship).

Unlock Toyota APR Performance Celica GTS:
Win the Point-to-Point (All-Wheel-Drive Event).

Unlock Porsche #17 Racing Porsche AG 962c:
Win the Endurance (Class R-P1 Championship).

Unlock Porsche #23 Alex Job Racing 911 GT3-RSR:
Win the Championship Series (Class B Championship).

Unlock Shelby Cobra 427 S/C:
Win the Championship Series (Classic Sports Car Event).

Unlock Toyota #27 GT-ONE TS020:
Win the Championship Series (Class R-GTS Championship).

Unlock Toyota Border MR2 Turbo T-bar:
Win the Point-to-Point (Front-Wheel-Drive Event).

Unlock Acura #42 RealTime Racing NSX:
Win the Championship Series (Club NSX Event).

Unlock Subaru Impreza WRX STi Spec-C (J):
Win the Point-to-Point (Rallisport Face Off).

Unlock Toyota 2000GT:
Win the Professional (Class D Championship).

Unlock TVR Tuscan R:
Win the Professional (TVR Tuscan Cup).

Unlock Volvo #25 At-Speed S60 R:
Win the Endurance Class D Championship.

Unlock Shelby Series 1:
Win the Professional (Shelby Cobra Cup).

Unlock Subaru Impreza 22B STi:
Win the Amateur (Rallisport Face Off).

Unlock Toyota AE86 Sprinter Trueno:
Win the Amateur (European Open).

Complete the following tasks to get the corresponding GamerScore.

All Cars from France - GamerScore 1:
Collect ALL of the cars from France in your Career garage.

All Cars from Korea - GamerScore 1:
Collect ALL of the cars from Korea in your Career garage.

All Cars from Spain - GamerScore 1:
Collect ALL of the cars from Spain in your Career garage.

All Cars from Sweden - GamerScore 2:
Collect ALL of the cars from Sweden in your Career garage.

All Cars from the United Kingdom - GamerScore 5:
Collect ALL of the cars from the United Kingdom in your Career garage.

Level 1 - GamerScore 5:
In Career mode reach Level 1.

Car Level 5 - GamerScore 5:
Achieve a car level of 5 in Career mode.

Crushing Victory - GamerScore 5:
Awarded to any driver who finishes the race with a lapped opponent.

Flawless Lap - GamerScore 5:
Awarded to the driver(s) who finish a lap with no time penalty against an opponent.

Flawless Race - GamerScore 5:
Awarded to the driver(s) who finish the race with no time penalty against an opponent.

Blowout - GamerScore 5:
Awarded to the driver who wins the race, beating the rest of the field by a full race section.

Hardcore - GamerScore 5:
Awarded to the single driver who wins the race with full Difficulty, including no Assists.

Hard Charger - GamerScore 5:
Awarded to the driver who starts in 8th place and comes in 1st place.

Natural - GamerScore 5:
Awarded to the single driver who wins the race with all Assists turned off.

Underdog - GamerScore 5:
Awarded to the driver who wins the race with a car in the lowest PI of the field.

All Cars from Italy - GamerScore 10:
Collect ALL of the cars from Italy in your Career garage.

Level 10 - GamerScore 15:
In Career mode reach Level 10.

All Bronze Arcade - GamerScore 15:
Get a Bronze medal in every Arcade Race.

All Cars from Germany - GamerScore 15:
Collect ALL of the cars from Germany in your Career garage.

All Gold Proving Grounds - GamerScore 15:
Get a Gold medal in every Career event of the Proving Grounds Race Type.

Car Broker - GamerScore 20:
Buy or sell 10 cars Online in the Auction House.

Level 20 - GamerScore 20:
In Career mode reach Level 20.

All Gold Manufacturer Club - GamerScore 20:
Get a Gold medal in every Career event of the Manufacturer Race Type.

All Cars from the United States - GamerScore 25:
Collect ALL of the cars from the United States in your Career garage.

All Silver Arcade - GamerScore 25:
Get a Silver medal in every Arcade Race.

All Gold Amateur Cup - GamerScore 25:
Get a Gold medal in every Career event of the Amateur Race Type.

Level 30 - GamerScore 30:
In Career mode reach Level 30.

All Gold Rivalry Face-Offs - GamerScore 30:
Get a Gold medal in every Career event of the Rivalry Race Type.

1,000,000 Online Credits - GamerScore 30:
Earn 1,000,000 'Online Credits' from Tournaments and Career races.

All Cars from Japan - GamerScore 30:
Collect ALL of the cars from Japan in your Career garage.

All Gold Semi-Pro Events - GamerScore 35:
Get a Gold medal in every Career event of the Semi-Pro Race Type.

All Gold Arcade - GamerScore 35:
Get a Gold medal in every Arcade Race.

Level 40 - GamerScore 40:
In Career mode reach Level 40.

All Time Trials Set - GamerScore 40:
In every Time Trial race beat the target time.

All Gold Factory-Spec - GamerScore 40:
Achieve a Gold medal in every Career event of the Pro Spec Race Type.

Level 50 - GamerScore 50:
In Career mode reach Level 50.

All Gold Regional Championship - GamerScore 50:
Get a Gold medal in every Career event of the Regional Championship.

All Gold Professional Series - GamerScore 60:
Get a Gold medal in every Career event of the Pro Series Race Type.

All Gold Endurance - GamerScore 70:
Get a Gold medal in every Career event of the Endurance Race Type.

All Gold All Race Types - GamerScore 75:
Get a Gold medal in every Career Race Type.