I am a semi decent modeler in studio and could create the following new cars to be added to the game, at least their physical models, not their code that makes them drive.
1977 Camaro
1968 Dodge Charger
2010 Chevy Camaro SS
2014 Chevy Camaro ZL1
2005 Mustang GT
2018 Dodge Challenger SRT Demon (to be fair this is just changing the hood and wheels on the hellcat and adding 100 horsepower)
1998 Toyota MkIV Supra A80
2000 Nissan Skyline GT-R (R34)
2001 Nissan Silvia S15
2013 Chevy Corvette ZR1