I've had a very quick go at most of the cars. I took them around Silverstone for a few laps.
I class them thusly, by comparable lap times:
Class C (about 2:38)
Mazda MX5 Cup
Toyota AE86 Tuned
Class B (about 2:35)
Nissan Skyline R34
Mazda RX7 Spirit R - great drifter!
Toyota Supra MK IV
Class A
Mazda RX7 Tuned (2:28)
Supra MK IV Time Attack (2:22)
The Class A cars are quite beastly and fun.
The Class C cars are sort of Toyota GT86-ish, underpowered and predictable.
The Class B cars make a good group of comparable cars which could be the 4th candidate for Season 12. Or for something a little faster and wilder, we could go the Supra MK IV Time Attack, which is still pretty easy to drive.