Ford (US)
Gulf Ford GT-40, 1968 Le Mans winner:
Nissan(Japan):
1967 Skyline KPGC10
Lotus/Caterham (UK):
Seven CSR (cossie motor
)
Audi (Germany):
Audi IMSA Quattro
Lamborghini (Italy/Europe):
1967 Lamborghini Miura
I'll go with your GT40
BTW, framebreaker
(Edit: not if you use the tags properly!)