The Smithsonian turned down America's last factory convertible of 1976
When Cadillac built what it billed as the final American convertible in 1976, the last one was offered to the Smithsonian. The trustees politely declined: it was not yet historic, though it might be in three generations. Within a few years, drop-tops were quietly rolling off Detroit's lines again.
The earliest cars were open by default, borrowing folding leather or cloth hoods from horse carriages; the word cabriolet itself comes from a light two-wheeled carriage with a fold-down top. Once mass-produced steel bodies arrived in the 1920s, closed cars became affordable and fully open ones retreated into the luxury market. Plymouth offered the first powered roof in 1939, worked by a pair of vacuum cylinders.
The Second World War revived the idea. American soldiers stationed in Britain and France fell for small roadsters like the MG Midget, unavailable at home, and through the 1950s and 1960s nearly every American maker offered an open version, from budget compacts to Packards. Sales peaked around 1965 and then slid. Air conditioning, sunroofs, faster highways full of wind noise, leaky fabric and tougher crash rules pushed the share down to two or three per cent, and brand after brand gave up.
Cadillac held on longest, building about 14,000 in its final year, the last 200 painted with a red, white and blue theme. Then specialist firms brought the style back: a sunroof company turned a Buick Riviera into a convertible that General Motors sold for 1982, Chrysler launched open K-cars that same year, and Ford revived the soft-top Mustang in 1983. Mazda's MX-5, launched in 1989, went on to sell more than a million, the most of any convertible.
Roof materials reveal the engineering. Early tops were cotton canvas woven so tightly it shed rain; by 1955 latex and butyl rubber fabrics dominated. Folding hardtops improve security at the cost of weight, complexity and boot space. Designers also fight the downsides of openness: wind blockers that cut noise by around 11 to 12 decibels, neck-level heating vents, and roll hoops that spring up from behind the seats if the car overturns.
Source: Convertible
