I know that seems oddly specific, but I've always kind of wondered what would happen if there was a Street Rod game set in anywhere but the U.S., which would (obviously) change the car set completely.
Region by region, here's my understanding of car "demographics" by country (in the 1970s):
Australia: Mostly Australian-built GMs (Holden, Ford, Chevrolet).
Asia (in an overall sense): I really don't know. Toyotas? AFAIK not as good as cars from the U.S. or Europe. Prime exceptions: Toyota Celica, Toyota S800, Mazda RX3.
Europe: European cars, mostly. Smaller and often more efficient and/or safer than their counterparts, since Asia's cars weren't QUITE up to spec yet. AFAIK for some reason, European V6s tended to be less efficient than their U.S.-made counterparts.