I grew up in the 70s in California and I can tell you all those Impalas, Novas, and Firebirds were still prevalent, not to mention the GTOs, the Challengers, etc . . . but then something happened and along came the Pinto, Vega, Gremlin, Pacer . . . etc . . .
I respect your decade choice for automobiles, but the 70s really marked the end for great looking cars. Good design was sacrificed for fuel efficiency. Plastic replaced metal, etc . . .