Okay, Gran Turismo 5 Prologue has a lot of cars for a demo game of a game. Cars in black have been seen in screenshots or have been confirmed by Polyphony through lists. Cars in red have been seen being photographed and tested by Sony/Polyphony Digital and may or may not be in Gran Turismo 5. Cars in green have been mentioned by magazines or in interviews as being in the game, yet have not been seen. Also may not be in Gran Turismo 5. Lets take a look:
AcuraA good amount of cars for a demo game I must say.
NSX ('91)
Alfa Romeo
147 TI 2.0 Twin Spark ('06)
Brera Sky Window 3.2 JTS Q4 ('06)
ASL
Garaiya (Autobacs JGTC, '03)
Audi
R8 R-Tronic ('07)
R8 (Audi Sport Team Joest Le Mans, '01)
R8 (PlayStation Team Oreca Le Mans, '05)
TT 3.2 Quattro ('03)
TT 3.2 Quattro ('07)
Bentley
Speed 8 (Le Mans, '03)
BMW
135i Coupe ('07)
V12 LMR (Le Mans, '99)
Z4 3.0i ('03)
Chevrolet
Corvette Roadster (C1-gen) (Craig Morrison, '06)
Daihatsu
Copen Active Top ('02)
OFC-1 Concept ('07)
Dodge
Viper GTS ('02)
Ferrari
599GTB Fiorano ('06)
F430 ('06)
Fiat
500
Ford
Model T ('15)
GT ('05)
GT LM Edition Spec-II ('04)
GT LM Edition Spec-II Test Car
Mustang GT Premium ('07)
Ginetta
G4 ('61)
Honda
Integra Type-R (DC5-gen, '04)
NSX Type-R (1st gen, '92)
NSX Prototype LM Edition ('02)
NSX (ARTA JGTC, '00)
NSX (Castrol Mugen JGTC, '00)
NSX (Raybrig JGTC, '00)
NSX (Loctite Mugen JGTC, '01)
NSX (Mobil 1 JGTC, '01)
NSX (Takata Dome JGTC, '03)
S2000
S2000 (Stephen Papadakis, '05)
Infiniti
Coupe Concept ('06)
G35 Coupe
Jaguar
XJR-9 (Le Mans, '88)
XKR R-Performance ('02)
Jay Leno
Tank Car ('03)
Lancia
Delta HF Intergrale Evoluzione ('91)
Lexus
IS-F ('07)
SC430 (Bandai SuperGT '06)
Lotus
Elise ('96)
Elise Sport 190 ('98)
Elise ('00)
Elise 111R ('04)
Mazda
Atenza Sport ('07)
787B (Le Mans, '91)
Eunos Roadster (NA-gen, '89)
Roadster (NC-gen, '05)
RX-7 Type-RS-R (FD-gen, '97)
RX-7 Spirit-R Type-A (FD-gen, '02)
RX-8 Concept LM Edition ('01)
Mercedes-Benz
(Sauber) C9 (Le Mans, '89)
300SL Coupe ('54)
SL55 AMG ('02)
SLR McLaren ('03)
Mitsubishi
Lancer Evolution IV GSR ('96)
Lancer Evolution IV (Rally Car, '97)
Lancer Evolution VIII (Rally Raid Car, '03)
Lancer Evolution VIII (HKS, '07)
Lancer Evolution IX GSR ('05)
Lancer Evolution X GSR Premium ('07)
Pajero Rally Raid (Dakar Rally, '85)
Nissan
(Nismo) Skyline GT-R R-Tune R1 (R33-gen, '99)
350Z ('03)
Fairlady Z (Motul Pitwork JGTC, '04)
Fairlady Z (Xanavi Nismo SuperGT, '06)
GT-R Proto concept ('05)
GT-R "Black Mask" prototype ('07)
R89C (Calsonic Le Mans, '89)
Silvia (C-West Razo JGTC, '01)
Skyline 1500 Deluxe (S50D1, '63)
Skyline 2000 GT-B (S54A, '67)
Skyline 2000 GT-R (KPGC110, '73)
Skyline GT-R (R34-gen, '91)
Skyline GT-R V-Spec II (R32-gen, '94)
Skyline GT-R V-Spec (R33-gen, '97)
Skyline GT-R V-Spec Nür (R34-gen, '02)
Skyline GT-R (Calsonic JGTC, '00)
Skyline GT-R (Loctite Zexel JGTC, '00)
Skyline GT-R (Pennzoil Zexel JGTC, '01)
Skyline GT-R (Xanavi Nismo JGTC, '03)
Skyline 350GT Sedan (V36-gen, '07)
Panoz
Esperante GTR-1 (FIA GT, '98)
Pescarolo
C60-Peugeot (PlayStation 2 Le Mans '03)
C60 Hybrid-Judd (GT4 PlayStation 2 Le Mans, '05)
Peugeot
307CC ('06)
905B Evo (Le Mans, '92)
Polyphony
Formula Gran Turismo ('04)
RE Amemiya
RX-7 (Aspara Drink JGTC, '04)
Renault
Clio Renault Sport V6 24V ('00)
Shelby
Cobra 427 ('67)
Subaru
Impreza WRX STi (Rally Car, '99)
Impreza WRX STi (Rally Car, '03)
Impreza WRX STi (Cusco Advan JGTC, '03)
Impreza WRX STi Spec-C Type-RA (GD-III gen, '05)
Impreza WRX STi (GE gen, '08)
Suzuki
Cappuccino ('95)
Swift Sport ('07)
Toyota
2000GT ('67)
88C-V (Le Mans, '88)
Celica GT-Four (ST205-gen Rally Car, '95)
Celica (WedsSport JGTC, '03)
Corolla (Rally Car, '99)
GT-One (Le Mans, '99)
MR-S (Autobacs JGTC, '00)
Prius G Touring ('03)
Supra (Tom's Castrol JGTC, '99)
Supra (Denso Sard JGTC, '00)
Supra (Tom's Castrol JGTC, '01)
Supra (au Cerumo JGTC, '01)
Supra (Esso Ultraflo JGTC, '01)
Supra (Tom's WoodOne JGTC, '03)
Trial
Celica SS-II ('03)
TVR
Tuscan Speed Six ('00)
Volkswagen
Golf IV GTi ('01)
Total cars: 92
[Via Ruliweb]