The DPI cars were confirmed in the last batch of car announcement, not sure why is it not on that list.
GT4 and GTE are two separate class, Codemasters has placed the GTE in Group 1 and GT4 in Group 2. It is rather annoying that the car list is listed by its career branch class and not its in game sub class.
Okay, so there are sub classes. Got it. I know that the DPi cars were announced relatively recently, that's why I was confused. So I'm guessing that they are under the "hidden up our sleeves" line.
Where do you see any Trans-Am cars?
Chevrolet Camaro Z28 Modified
Ford Mustang Mach 1 Modified <-(Though I remember the 302 being use)
Pontiac Firebird Modified
Just as examples.