Seeing as how I didn't know this post was a thing until now, hopefully I'm not too late to request something. I'm going to list a bunch of cars. They are in no particular order, but Ithey are just some things I'd personally like to see in the game.
Porsche 911 Targa (930, 991, 992 all work)
Porsche Cayman
Porsche Boxster
BMW E46 (M3 as well as a 330i Sedan and/or wagon model if it's possible)
BMW E30
BMW E36
BMW E39
BMW M1
Aston Martin DBS Superleggera
Porsche 911 (930 generation. I know a more modern variant is already confirmed)
Spyker C8 Laviolette (along with any and every other Spyker in existance. Just yes.)
Bugatti Chiron
Lamborghini Miura
Lamborghini Gallardo
Lamborghini Murcielago
Lamborghini Aventador
Lamborghini Urus
VW Golf GTI (any gen)
Mercedes-Benz G63 AMG
Rolls Royce (literally any of them)
Bentley Continental Supersports
Jaguar F-Type
Land Rover Defender (old and new)
Land Rover Range Rover
Land Rover Evoque
Hummer H3 (V8. the in-game H3 has the 5-cylinder engine, which is way underpowered. The V8 would be on par with every other car in its class. Could be easily done as well, you only need to edit the performance figures)
Jeep Grand Cherokee Trackhawk
Mini Cooper S/JCW
More up-to-date McLarens including the 570S, 600LT, 720S, Senna
McLaren F1
On top of these, I would also like to see some more retro cars such as-
Chevrolet Bel-Air 1957
1929/1930 Ford Model A (These have several different body styles, all of which would be interesting to see in the game)
Cadillac Series 62
Kaiser Darrin
Fiat 500 (the original 500)
Porsche 356
Aston Martin DB5
Aston Martin V8
Bentley Turbo R
1957 Plymouth Fury/Belvedere (these two are actually the same model, just one has two doors and the other has 4)
Maserati 3500 (not fast but damn beautiful)
Bugatti Type 57C
1935 Rolls Royce Phantom 1
Rolls Royce Silver Cloud 1/2
I reserve the right to add more to this list as I come up with more. Obviously I'm not expecting to see every one of these, but any of them would be good additions.