Much has been written about the Corvair; some bad and some good. Urban legend grew around the car's story and much of it is false.
The engines, for instance, were actually quite reliable and not affected fatally by fan belt breakage. Potential loss of control problems (rear swing axle tuck) were solved by the 1964 model year. Ralph Nader's book had nothing to do with the demise of the car either. GM cancelled the product line 18 months before his book came on the shelves. Here's the true story.
By the late 1950s the Volkswagen was being noticed in Detroit. Big Three executives felt a response to small, efficient European cars was needed, so they all instituted projects to address that burgeoning market. Ford created the Falcon, Chrysler the Valiant and GM the Corvair. All three were well-conceived products but the Corvair was, by a long shot, the most innovative.
GM executives wanted to create a "compact" car that was more innovative than anything the company had ever produced, and engineers were champing at the bit to build an air-cooled, flat (pancake) 6 cylinder engine. The decisions were made, therefore, to design and produce a rear-engined car that would have exceptional handling and braking performance when compared to traditional automobiles. Bear in mind that while these decisions were being made the showrooms were sporting '58 Buicks, Cadillacs, Oldsmobiles, Pontiacs and Chevrolets. All these cars were huge, heavy and chrome-laden. The Corvair, as the new car would be called, would change all the rules.
The 1960 model year Corvair sold extremely well. It was cute, compact, comfortable and cheap (inexpensive, that is). It was a little hard to get into and out of and, much like the VW, the heater in winter left something to be desired. GM engineers quickly solved that problem, however, with the addition of an "aircraft-type" gasoline heater. Owners accepted the concept but quickly realized that the Corvair's already unimpressive fuel mileage quickly got worse when the heater was used.
Drivers of the Corvair loved its quick, light steering and "peppy" (if not fast) acceleration. They soon accepted the engine's tendency to leak oil and throw fan belts as the cost-of-doing-business, and it was the rare owner who didn't travel with an extra can of oil and at least one new belt. Contrary to popular belief at the time, if a fan belt broke the engine would not easily overheat and seize up. The cylinder heads were actually engineered to take over 600 degrees F without warping, something no V8 could ever do.
Power output from the Corvair's flat 6 engine was modest, starting from 90 hp and then gradually creeping to 110 in the standard car. Monza Spyder (1962) models came with turbochargers that increased the little engine's power to 140 hp and, in 1965, to 180 hp. These were not terribly popular options but those who owned them loved them.
The basic architecture of the Corvair doomed it, not Ralph Nader. The engine was limited in power and therefore in its ability to carry optional accessories easily. Air conditioning, power steering and brakes, etc., were difficult to engineer in a cost-effective way. The car's platform was weight-sensitive also.
Meanwhile, Ford was introducing the Mustang, a car that could be optioned in any way a customer wanted. This made it everything from bare-bones transportation to luxury-performance, while the Corvair could only be had with some extra trim and maybe an air conditioner or turbocharger. GM management realized, in late 1963, that the Corvair could never compete with the "pony car" phenomenon and it would have to be cancelled as a product platform. The new platform designed to compete with Mustang would be called the Camaro.
Eighteen months AFTER this decision Ralph Nader's book, "Unsafe at Any Speed," hit the newsstands. It cited some handling problems with early Corvairs, all of which had been solved well before the book came out. GM stupidly tried to silence Nader and the story took off from there. The only effect Nader had on the Corvair is that GM kept the car in production until 1969 (rather than ending it in 1966) just to save face.
Corvairs have never become expensive collectibles but there is a solid, devoted following for the car. They will always be considered cute, fun to drive and a very interesting part of automotive history.