The additional cars I spotted:
2017 Bentley Continental Supersport
1981 BMW M1
2015 BMW i8
1975 Ford Bronco
19XX Ford Escort XR3
2015 Land Rover Range Rover Sport SVR
2013 McLaren P1
2013 Mercedes-Benz A45 AMG
2014 Porsche 918 Spyder
2005 Subaru Impreza WRX STi
So far we’ve seen about 20% of the car count and less than half of the manufacturers. We still have yet to see FM7 Division cars from (with examples):
Hot Rod Revival (Ford De Luxe, '57 Chevy)
Nostalgic Drag Racers
Classic Street Muscle & Historic Road Racing
Rebirth of Muscle
Sport Touring (modern muscle, Giulia, C63)
(There are 86 of the above from FM7. Other than the U.S.-made offroaders, we have seen the Shelby Cobra Daytona and Dodge Viper ACR)
Early Sport Luxury (1990s BMW) & Sport Luxury (RS5/6, M5/6, Rolls)
Early Sport Touring (1990s Alfas) & Sport Touring Icons (S4, M3)
Hot Hatch Genesis & Hot Hatch Icons
Modern SUV (out of nearly two dozen we’ve only seen the Land Rover SVR)
Sport Compact Icons (only the one Silvia out of two dozen 1990s JDM)
Vintage Sport GT (Montreal, V8 Vantage, 365 GTB/4, Miura)
That looks like potential for theme week reveals again. Both FH3 and FM7 car reveals began 5 weeks after E3. In FM7 the weeks were themed by:
Porsches, Lambos, Ferraris
Vintage week
JDM & customization
American
European
Forza Edition cars
Race cars
Previous Forza manufacturers we haven’t seen yet:
Partners:
AMG TD Warthog
Chryslus
Hot Wheels
Quartz Regalia Fast & Furious editions
American (in game terms)
AMC
Baldwin
Buick
Cadillac
Devon (last seen as DLC in FH1)
Chevrolet
Chrysler
Eagle (U.S.)
GMC
Hennessey
Hummer
Infiniti
Lexus
Lincoln
Mercury
Meyers
Mosler (last seen in FM4)
Oldsmobile
Panoz (last seen in FM4)
Plymouth
Pontiac
Robby Gordon
Rossion (last seen in FM4)
Saleen
Scion
SSC
Terradyne
Tesla
Asian:
Datsun
Hyundai
Kia
Mazda
Suzuki (last seen in FM4)
TAMO
Toyota production cars
European:
Abarth / FIAT
Alfa Romeo
Ascari
Auto Union
BAC
Bertone (last seen in FM4)
Caparo (last seen as DLC in FM6)
Caterham
Citroen
De Tomaso (last seen in FM4)
Devon
Donkervoort
Gumpert
Holden / HDT / HSV
Joss (last seen as DLC in FH1)
Maserati
Noble
Opel
Peugeot
Radical
Reliant
Renault
Rolls-Royce
RUF
Saab (last seen in FM4)
SEAT (last seen in FM4)
Spada (last seen in FM4)
Spania GTA
Spyker (last seen in FM4)
Sunbeam
Talbot
Triumph (last seen as DLC in FM4)
Ultima
Volvo
W Motors
Wiesmann (last seen in FM4)
Zenvo
It has been confirmed that the pre order cars are only tuned versions of cars that are in the game like in FH3. So the DB11 and the GT3RS will be avaiable to everyone at launch