Cars were even heavier in the 30s, 40s, 50s, and 60s. They had steel bodies, chrome bumpers, massive trunks, V8 engines too. It wasn't until the oil crisis in the late 70s and the introduction of Japanese brands that cars got small.

Take a look at a 1950s Coup de Ville, Buick Roadmaster or any other famous models from that era. All pushing 4K, sometimes 5K pounds.