Acura ARX-05/ARX-06 > to be added (I know it's almost impossible, but one can dream)
Alpine A480 > to be added
Alpine A424 > to be added (but same situation of the Acura)
Aston Martin DBR 1-2 (aka Lola-Aston Martin B09/60) > to be added
Audi R8C/R8R '99 > to be added (those cars marked Audi debut in endurance racing)
Audi R8S '00/'01 > to be added (with it began the Audi dominion at Le Mans and in endurance racing in general)
Audi R8S '04 (PlayStation team Oreca) > to be added (too iconic with that livery)
Audi R18 '11 > it should stay (it's the winner of the epic battle vs Peugeot at the 2011 Le Mans 24H)
Audi R18 e-Tron '14 > to be added (to me maybe the best looking version of the R18, very appreciated in Forza Motorspor 6 IIRC)
Audi R18 '16 > it should stay (as of now, it's the latest Audi LMP car; maybe they could add updgrade parts)
Bentley Exp Speed 8 ('01/'02)/Speed 8 ('03) > to be added (those cars marked the "Bentley Boys" return and win at Le Mans)
BMW V12 LMR '99 > to be added (winner of the 1999 Le Mans 24H)
BMW MHybrid V8 > to be added (but same situation already described for Acura)
Cadillac DPI-VR/V-Series.R > to be added (but I think there is a sort of exclusive license with Forza)
Courage C60-Peugeot turbo (team Pescarolo) > to be added
Dallara SP1-Judd (Doran Lista Racing) '02 > to be added (winner of the 2002 Daytona 24H)
Dome S101/S102/S102.5 > to be added. This LMP car is japanese (sometimes 100% japanese, when it raced with Mugen engines), I don't know why PD never thought about it
Ferrari 333SP > to be added (winner of many races around the world and also of the FIA WSC in the early 2000s)
Ferrari 499P > to be added (but same situation already described for Acura and BMW)
Jaguar XJR-9 > it should stay
Jaguar XJR-14 > to be added
Mazda 787B > it should stay (winner of the 1991 Le Mans 24H)
Mazda RT24-P DPI > to be added, underestimated but winning car (winner of two editions of the 6H of the Glen, one Sebring 12H and one Petit Le Mans)
Nissan R92 CP > it should stay
Nissan GT-R Nismo LM > could we please forget this car? please... maybe also Nissan would be happy...
Nissan DPI (aka Ligier-Nissan DPI) > an underestimated but winning car (winner of the 2017 Sebring 12H and of the 2018 Petit Le Mans)
Nissan R390 '98/R391 '99 > to be added (but maybe R390 would go in Gr. 2)
Panoz GTR-1/Spyder (aka Roadster S)/LMP07 > to be added because yes
(too iconic cars)
Pescarolo C60/C60H > to be added
Peugeot 905 > to be added
Peugeot 908 HDi FAP > maybe to be replaced with the
908 '11 or with the
908 Hybrid4 (that never raced, though)
Peugeot 9X8/9X8 "Evo" > to be added
Porsche 962 > it should stay
Porsche 911 GT1 '98 > to be added (winner of the 1998 Le Mans 24H)
Porsche 919 Hybrid > it should stay
Porsche 963 LMDh > to be added (but same situation already described for Acura, BMW, Cadillac and Ferrari)
Sauber Mercedes C9 > it should stay
Toyota Gr. 1s > they must stay