What’s the most impressive stunt that General Motors pulled off in 1957? The fast fuel-injected Chevy and Pontiac? The opulently pricey Caddy Eldorado Brougham? Or the luxurious Bel Air custom?

When Steve Thatcher was in high school 45 years ago, he bought his neighbor’s bright yellow 1957 Chevy Bel Air for $1,500. : ...