The very save assumption is that if it was on GT6 as a premium car, it will most likely come.Going by previous patterns and my own gut feeling...
Essentials:
Honda Civic Type R (additional generations)
Honda NSX-R (facelift)
Mazda MX-5 (additional generations)
Mitsubishi GTO Twin Turbo
Mitsubishi Lancer Evolution (additional generations)
Nissan Fairlady Z (additional generations)
Nissan Silvia (multiple generations)
Subaru Impreza WRX STI (additional generations)
Toyota Sprinter Trueno
Also possible:
Honda Integra
Honda S800
Mazda Cosmo
Mazda RX-8
Mitsubishi FTO
Nissan Skyline GT-R (older generations)
Suzuki Cappucino
Toyota Sports 800
Toyota Celica (multiple generations)
Less likely:
Honda Prelude
Mazda RX-7 (first generation)
Mitsubishi Starion
Nissan Stagea
Subaru Legacy B4
Subaru Alcyone SVX
Toyota Chaser
Toyota Supra (older generations)
Toyota MR-2 (additional generations)
The list then include:
- Both of MX5 generations: Original 1992 (either one) and 2007
- Subaru Impreza 2005 and 2007 or its equivalent.
- Mitsubishi Evolution 6 (All its variants) and 8.
- Honda Civic Type R 1997 and 2006
- Honda Integra Type R DC5 2004
- Honda S2000 2006
- Nissan Skyline Sedan 350GT and 370GT
- Lexus LFA 2010
- Lexus ISF 2007
- Mazda RX8 2007
- Nissan 350Z and 370Z
- Suzuki Cappuccino (either one)
- Mazda Autozam AZ1
- Nissan Silvia Spec R 2002
- Honda CRZ
- Infiniti G35 (Manufacturer with only one VGT cmon)
- Opera Perfomance 350Z
Less likely to include a concept car of the past. Also less likely to add variants already in game, includes:
- Efini RX7
- Acura NSX 1991 and Honda NSX Type R 2002
- Toyota 86 and Subaru BRZ 2010
- Nissan GTR 2007, 2009, 2012, and Nismo 2014.