here's a list that might help you, its a quick made list, so don't expect to much of it...
Concepts
Acura RS-X (Type R Meeting, Beginner)
Nissan Z (Gran Turismo World Championship, Amateur)
Mazda RX-8 (NA Race Race of NA Sports, Amateur)
LM-Cars
Mitshubishi FTO LM Race Car (Dream Car Championship, Amateur)
Mazda RX-7 LM Race Car (Dream Car Championship, Amateur)
Honda S2000 LM Race Car (Dream Car Championship, Amateur)
Subaru Impreza LM Race Car (Dream Car Championship, Amateur)
Toyota Altezza LM Race Car (Altezza Championship Race, Amateur)
JGTC
Arta NSX Race Car (All Japanese GT Championship, Amateur)
Castrol Mugen NSX Race Car (All Japanese GT Championship, Professional)
Raybrig NSX Race Car (Gran Turismo All Stars, Amateur)
Denso Supra Race Car (All Japanese GT Championship, Amateur)
Castrol Toms Supra Race Car (Vitz Race, Professional)
Calsonic Skyline Race Car (All Japanese GT Championship, Amateur)
Loctite Zexel Skyline Race Car (All Japanese GT Championship, Amateur)
Formula 1
F686/M (Get All Golds, Professional)
F687/S (Formula GT Championship, Professional)
F688/S (Formula GT Championship, Professional)
F090/S (Formula GT Championship, Professional)
F094/H (Get All Golds, Endurance)
Rally
Mitshubishi Lancer EvoVI Rally Car (Evolution Meeting, Amateur)
Mitshubishi Lancer EvoVII Rally Car (4WD Challenge, Professional)
Subaru Impreza Rally Car (Tahiti Maze II, Rally)
Subaru Impreza Rally Car Prototype (Super Special Stage 5 (wet II), Rally)
Ford Escort Rally Car (Tahiti Maze, Rally)
Ford Focus Rally Car (Smokey Mountain, Rally)
Toyota Celica Rally Car (Rally Challenge, Rally)
Toyota Corolla Rally Car (Rally Challenge II, Rally)
Peugeot 206 Rally Car (Swiss Alps, Rally)
Suzuki Escudo Pikes Peak Version (Get All Golds, Rally)
Street Racers
Mitshubishi Lancer EvoIV GSR (Evolution Meeting, Beginner)
Mitshubishi Lancer EvoV GSR (Buy)
Mitshubishi Lancer EvoVI GSR (Gran Turismo World, Amateur)
Mitshubishi Lancer EvoVI GSR T.M.E. (Buy)
Mines Lancer EvoVI GSR (Turbo Race of Turbo Sports, Amateur)
Mitshubishi Lancer EvoVII GSR (4WD Challenge, Amateur)
Subaru Impreza Sedan WRX Sti VI (American Championship, Amateur)
Nismo Skyline GT-R S-tune (All Japan GT Championship, Professional)
Nissan Skyline GT-R V-spec II (R33) (Gran Turismo World, Beginner)
Mines Skyline GT-R N1 V-spec (Gran Turismo All Stars, Amateur)
Nismo Skyline GT-R R-tune (Gran Turismo All Stars, Amateur)
Deutsche Tourenwagen Meisterschaft (DTM)
Mercedes Benz CLK Touring Car (Legend of Silver Arrow, Amateur)
Opel Calibra Touring Car (Gran Turismo World, Professional)
Opel Astra Touring Car (German Touring Car Challenge, Amateur)
American Racers
Dodge Viper GTS-R (Get All Golds, Amateur)
Chevrolet Corvette C5R (Super Speedway 150 Miles, Endurance)
Chevrolet Camaro Race Car (American Championship, Amateur)
Ford GT40 Race Car (Gran Turismo World, Professional)
Cup Cars
Volkswagen Beetle Cup Car (German Touring Car Challenge, Amateur)
Volkswagen Lupo Cup Car (German Touring Car Challenge, Amateur)
Renault Clio Sport Cup Car (Super Speedway 150 Miles, Endurance)
Toyota SuperAutobacs MR-S (All Japanese GT Championship, Professional)
Spoon Sports S2000 Race Car (Stars + Stripes Grand Championship, Amateur)
Nissan C-West Razo Silvia (Special Stage Route 11, Endurance)
Muscle Cars
Ford GT40 (Gran Turismo All Stars, Amateur)
Shelby Cobra (Spider & Roadster Championship, Professional)
Light Sports Cars
Mazda MX-5 Miata (Clubman Cup, Beginner)
Mazda MX-5 Miata 1.8 RS (Spider/Roadster Cup, Beginner)
Toyota MR-2 (MR Challenge, Beginner)
Toyota Celica SS-II (New) (Altezza Race, Beginner)
Mercedes SLK (Legend of Silver Arrow, Beginner)
Audi TT 1.8T quatro (Tourist Trophy, Beginner)
Spoon Sports S2000 (Type R Meeting, Amateur)
Mugen S2000 (Type R Meeting, Amateur)
Honda S2000 (Type R Meeting, Amateur)
Mitshubishi FTO GP Version R (Japanes Championship, Amateur)
Lotus Elise 190 (Elise Challenge, Professional)
TVR Griffith 500 (TVR Tuscan Challenge, Professional)
RUF 3400S (German Touring Car Challenge, Amateur)
Sports Cars
Chevrolet Camaro SS (Stars + Stripes Grand Championship, Beginner)
Toyota Supra RZ (Vitz Race, Professional)
Mazda RX-7 Type RZ (Japanese Championship, Amateur)
Mazda RX-7 Type RS (American Championship, Amateur)
Honda NSX Type R (Type R Meeting, Amateur)
Jaguar XKR Coupé (Buy)
Aston Martin V12 Vanquish (British GT Championship)
Aston Martin V8 Vantage (Buy)
Aston Martin DB7 (Buy)
Tommy Kaira ZZ-II (MR Challenge, Professional)
RUF RGT (Boxer Spirit, Professional)
RUF CTR2 (Turbo Race of Turbo Sports, Professional)
Pagani Zonda C12S (NA Race of NA Sports, Professional)
Dodge Viper GTS-R Concept (Gran Turismo All Stars, Professional)
TVR Speed 12 (Polophony Digital Cup, Pofessional)
Super Sports Cars
Toyota GT-One Road Car (Gran Turismo World, Amateur)
Nissan R390 GT1 Road Car (Gran Tursimo World, Professional)
Jaguar XJ220 Road Car (Mistral 78 Laps, Endurance)
GT1
Toyota GT-One Race Car (Dream Car Championship, Professional)
Nissan R390 GT1 Race Car (Gran Turismo All Stars, Professional)
Jaguar XJ220 (Gran Turismo World, Professional)
Panoz Esperante GTR (Dream Car Championship, Professional)
Mazda 787B (Like The Wind, Professional)
Race Cars
Pagani Zonda Race Car (All Japan GT Championship, Professional)
Lister Storm V12 Race Car (Trial Mountain Endurance, Endurance)
Tickford Falcon XR8 Race Car (Super Speedway 150 Miles, Endurance)
greetz...
) or knows were i can get a list of all the cars that you can ONLY win. it would be helpful for me so i know wich car to go with on prize event 
