Every race you can win something. You can either win money and a car, or just money.
Easy   - One Race   - N/A
Normal - One Race   - N/A
Hard   - One Race   - N/A
Expert - Five Races - N/A - You don't win any car in the races, but you do win money

LEGEND
[R]   Racing model
N/A   You don't aquire a Car when you win the race
VS.   Versus (Rally Events only)
RC    Recommended Car to use
TBA   To be Announced
(J)   Japanese Model

Personally, I recommend using the Escudo Pikes Peak car for EVRY free race to have hilarious edge over your competition.

Event  [Recommended Car(RC)]  Track           Car/Prize

GRAN TURISMO LEAGUE

Japan Nationals: [RC- Civic 3-Door Si]                       
N/A for all

US Nationals: [RC- Civic 3-Door Si]                       
N/A for all

French Nationals: [RC- Civic 3-Door Si/Volkswagen New Beetle (Tuned)]                       
N/A for all

UK Nationals: [RC- Civic 3-Door Si/Volkswagen New Beetle (Tuned)]                       
N/A for all

Italian Nationals: [RC- Civic 3-Door Si/New Beetle (Tuned)]                       
N/A for all

German Nationals: [RC- Civic 3-Door Si/New Beetle (Tuned)]                       
N/A for all

Euro League: [RC- Lancer Evolution V or VI (Tuned)]                       
Apricot Hill           [R]Castrol Supra GT '96                       
Grand Valley           [R]Zexel Skyline GT '97                       
Rome Circuit           [R]Kure R33 GT '97 

Pacific League: [RC- Lancer Evolution V or VI (Tuned)]                       
Midfield Raceway       [R]Nissan 300ZX GTS '97                       
Seattle Circuit        [R]Mazda RX-7 LM Edition                       
Laguna Seca            [R]Drag 180SX

Gran Turismo World League - IA [RC- Escudo P.P Edition/Unisia Skyline]                      
Trial Mountain                         Prize Cars:                    
Laguna Seca Raceway    [R]Castrol Mugen NSX GT '99                     
Apricot Hill                     [R]R390 GT1 LM Race Car '99                     
Rome Circuit                  [R]Calsonic GT-R GT '99                     
Midfield Raceway           [R]GT-ONE '98 (?) 

SPECIAL EVENTS

Sunday Cup: [RC- Civic 3-Door Si (Tuned)]                       
N/A for all

Clubman Cup: [RC- Civic 3-Door Si (Tuned)]                       
N/A for all

FF Challenge: [RC- Civic 3-Door Si (Tuned)/Mitsubishi FTO '94 (Tuned)]                       
Tahiti Road            Mugen Accord SiR-T                       
Midfield Raceway       Tom's T111                       
Trial Mountain         Mugen Prelude Type-S

FR Challenge: [RC- Nissan Skyline GTS-t Type M]                       
Clubman Stage R5       Sileighty                       
Special Stage R5       Nismo 270R                       
Midfield Raceway       Mazda RX-7 GT-C '99

Mid-engine Challenge: [RC- Atlantique 400 GT/Acura NSX Type S]                       
Grand Valley East      TRD2000GT                       
High Speed Ring        Tom's T020                       
Red Rock Valley        [R]GT40 Race Car

4WD Challenge: [RC- Lancer Evolution V or VI/Skyline GT-R]                       
Seattle Short          Legacy Wagon GT-B '96                       
Seattle Circuit      Nismo 400R Preceiding Model                       
Laguna Seca           Mine's R32.5 Skyline GT-R

Lightweight "K" Cup: [RC- Mazda Demio GL-X/Cooper Mini (Tuned)]                       
Rome Short           Mugen Beat                       
Seattle Short        Mazda Demio A-spec '97                       
Tahiti Road          Mugen CR-X II

Compact Car World Cup: [RC- Mitsubishi Mirage Cyborg ZR'99/Audi TT 1.8T quattro]                  Rome Short           Vitz F '99                       
Seattle Short        Clio 16V                       
Autumn Ring          Lupo 1.4

Luxury Sedan Cup: [RC- [R]Mitsubishi FTO LM Ed./Anything else you want]                        Rome Circuit         Accord Type-R                       
Special Stage R5     Chaser TRD Sports X30                       
High Speed Ring      GT-R 4Door Tuned by Nismo

Muscle Car Cup: [RC- [R]Mitsubishi FTO LM Ed./[R]Escudo P.P Edition]                       
Seattle Short        PT Spyder                       
Seattle Circuit      Cobra 427 '67                       
Laguna Seca          Phaeton (Dodge)

Convertible Car Cup: [RC-[R]Mitsubishi FTO LM Ed./Cobra 427 '67/Skyline GTR V-Spec(R-34)]   Tahiti Road          MX-5 Miata A Spec                       
Grindelwald          MR-S Show Version '97                       
Trial Mountain       [R]Concept Car LM Edition

Historic Car Cup: [RC- Audi TT 1.8T quattro]                       
Tahiti Road          Mugen CR-X III                       
Rome Circuit         Europa                       
Grindelwald          XYR '99

Station Wagon Cup: [RC- Imprezza Wagon]                       
Rome Short           Impreza Wagon STi Ver.V '98                       
Super Speedway       Mugen Accord Wagon                       
Special Stage R5     Stagea 260RS Tuned by Nismo

'80s Sports Car Cup: [RC-A good car by Nismo because of a "bitch car" that you'll race sometimes]  Trial Mountain       Mugen Ferio                       
Special Stage R5     Mugen CR-X III                       
Deep Forest          Mugen Civic Type-R                      
Seattle Circuit      Mugen Integra Type-R                       
Tahiti Road         [R]Skyline Silhouette                                               

Grand Touring Car Trophy: [RC- Lancer Evolution VI RS '99/FTO LM Ed.]                       
Red Rock Valley     [R]Daisin Silvia GT '99                       
Grand Valley        [R]Mugen NSX GT                       
Midfield Raceway    [R]Unisia GT-R GT '99

Pure Sports Car Cup: [RC-See "80's Sports Car")]                       
Laguna Seca         Angel T01                       
Deep Forest         ZZIII                       
Trial Mountain      Tuscan Speed 6

Tuned NA Car No.1 Cup (prize car changes regularly): [RC- TBA...]                       
Autumn Ring      Prize Cars:                       
Grindelwald      Spoon Civic Type-R                       
Laguna Seca      Spoon Integra Type-R         MX-5 Miata B Spec       MX-5 Miata C Spec Tuned

Turbo Car No.1 Cup(prize car changes regularly):[RC-[R]Escudo P.P Ed.]                       
Special Stage R5     Prize Cars:                       
Test Course          [R]R33 Drag GT-R                       
Deep Forest          Mine's R33 Skyline GT-R      Nismo 400R

Gran Turismo All Stars: [RC- [R]Escudo Pikes Peak Ed./Unisia JECS Skyline GT-R]                      Super Speedway       Mine's Lancer Evolution V                       
Special Stage R5     Mine's R34 Skyline GT-R                       
Red Rock Valley      Speed 12                       
Rome Circuit         [R]ZZII                       
Laguna Seca          R390 GT1 Road Car '97

Super Touring (prize car changes regularly): [RC- Your fastest and best 4WD car]                       
Apricot Hill               Prize Cars:                       
Trial Mountain       TRD3000GT                       
Laguna Seca          Tom's Supra                       
Deep Forest          Camaro Z28 30th Anniversary                       
Rome Circuit

GT 300 Championship   (race series): [RC- See above]                       
Grand Valley East     Prize Cars (must complete all races):                       
Laguna Seca          [R]Momo MR2 GT '99                       
Deep Forest          [R]Weds Celica GT '99                       
Midfield             [R]BP Trueno GT '99                       
Apricot Hill         [R]Zanavi Silvia GT '99

GT 500 Championship (race series): [RC- See above]                       
Laguna Seca         Prize Cars (must complete all races):                      
Super Speedway        [R]Arta GT-R GT '99 (?)                      
Rome Circuit          [R]Cerumo Supra GT '99                      
Trial Mountain        [R]Takata NSX GT '99                      
Apricot Hill          [R]STP Viper GT '99 

RALLY EVENTS(N/A for all)

Green Forest Roadway: [RC- Tigra Ice Race Car]                             
VS. Astra Sri 2.0i 16V                                    
VS. Escort Rally Car                                      
VS. Focus Rally Car          

Smokey Mountain South: [RC- Tigra Ice Race Car]                             
VS. Storia                                                
VS. Delta Integrale                                       
VS. Delta                   

Tahiti Maze: [RC- Tigra Ice Race Car]                             
VS. Celica                                                
VS. Rally Car                                             
VS. Lancer Rally Car         

Smokey Mountain North: [RC- Tigra Ice Race Car]                             
VS. Saxo                                                  
VS. Magane Coupe            

Tahiti Dirt R3: [RC- Tigra Ice Race Car]                             
VS. Pulsar
VS. Stratos
VS. Corolla Rally Car        

Pikes Peak Downhill: [RC- Escudo P.P Edition]                             
VS. 306 S16 
VS. Sratos 
VS. Lancer EVO IV GSR 

Pikes Peak Hill Climb: [RC- Escudo P.P Edition]                             
VS. RS200 Rally Car    
VS. Cultus Pikes Peak 
VS. Escudo Pikes Peak

Smokey Mt. North Reverse:[RC- Escudo P.P Edition]                             
VS. Pulsar
VS. Celica      
VS. Lancer Rally Car 

Tahiti Dirt R3 Reverse: [RC- Tigra Ice Race Car]                             
VS. Familla         
VS. Impreza Rally Car   
VS. Tiagra Ice Race Car 

ENDURANCE

Grand Valley 300 KM          [R]Impreza Rally Car        [R]R390 GT1 LM Race Car '97
Apricot Hill 200 KM          Lancia Stratos        [R]Viper GTS-R
Seattle Circuit 100 Miles    [R]GT90               [R]Escort Rally Car
Laguna Seca 200 Miles    [R]3000GT LM Edition '99     [R]Celica Rally Car
Rome Circuit 2 Hours    [R]Corolla Rally Car'97  [R]Altezza LM Edition
Trial Mountain            [R]Denso Sard Supra '99
SS Route 5 All-Night    [R]Cerbera LM Edition      [R]Lancer Evolution VI
Winable Car List