Traded cars in every 3-5 years.......
Maybe in your area but when I was growing up as a kid in the mid 70's the newest cars on my two block long street were a used Ford Maverick and a used 70 Pontiac Catalina. Everyone else drove old cars because thats all they could afford. Examples I saw were 59 Thunderbird, 62 Old Cutlass, 65 Tempest, 66 Belair, 63 Impala, 66 Olds Ninety Eight, 62 Galaxy, 66 Coronet, 66 VW squareback, 60 Dodge, 66 Mustang, 69 Marquis, plus my parents 66 Caprice wagon and 65 Chevy II sedan. And this was just an average working class area not poverty row. My dad drove his 53 Buick Roadmaster he bought new until 66 when he bought the Caprice wagon, and drove that until 79 when he bought a new Buick wagon, then drove that until 1990 with another Buick wagon until 2000 when he bought a 1990 Volvo 240 wagon.